1. G-1
Geometry Standard 1:
Students demonstrate understanding by identifying and giving examples of undefined
terms, axioms, theorems, and inductive and deductive reasoning.
WEBSITE: http://www.brainpop.com/math/geometryandmeasurement/
ANNOTATION: Brainpop can be found on ED1 stop on the Contra Costa County
Office of education website. Short flash videos with quizzes and extension activities
target basic geometry concepts.
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2. G-2
Geometry Standard 2:
Students write geometric proofs, including proofs by contradiction.
WEBSITE: http://zimmer.csufresno.edu/~larryc/proofs/proofs.contradict.html
ANNOTATION: This site is a comprehensive definition of proofs by contradiction. It is
appropriate for students who have interest in the topic.
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3. G-3
Geometry Standard 3:
Students construct and judge the validity of a logical argument and give counterexamples
to disprove a statement.
WEBSITE: http://www.learn360.com/Search.aspx?
Subject=9331423&ID=132207&GradeLevel=3360056
ANNOTATION: Learning 360 is a compilation of standards articulated videos. They
are available on Ed 1 stop on the Contra Costa County Office of Education site. This
lesson addresses geometry basics with a special emphasis on deductive and inductive
reasoning and judging the validity of logical arguments. There is some advertising at the
beginning of the video, so it may be a good idea to cue it to the instructional delivery.
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4. G-4
Geometry Standard 4:
Students prove basic theorems involving congruence and similarity.
WEBSITE: http://nlvm.usu.edu/en/nav/frames_asid_165_g_1_t_3.html?
open=instructions
ANNOTATION: This virtual manipulative allows the user to construct two triangles
from various combinations of sides and angles. The theorems are provided for reference.
This simulation may be helpful for struggling learners.
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5. G-5
Geometry Standard 5:
Students prove that triangles are congruent or similar, and they are able to use the
concept of corresponding parts of congruent triangles.
WEBSITE: http://www.saltire.com/applets/simtri1/simtri1.htm
ANNOTATION: This has applets that address basic geometry concepts. This interactive
applet demonstrates the concept of similarity between corresponding parts of congruent
triangles.
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6. G-6
Geometry Standard 6:
Students know and are able to use the triangle inequality theorem.
WEBSITE: http://www.onlinemathlearning.com/triangle-inequality.html
ANNOTATION: This site offers text, graphics, simulations, worksheets and interactive
activities on mathematical concepts. This lesson addresses the triangle inequality
theorem. This site is appropriate for struggling learners.
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7. G-7
Geometry Standard 7:
Students prove and use theorems involving the properties of parallel lines cut by a
transversal, the properties of quadrilaterals, and the properties of circles.
WEBSITE:
http://mathforum.org/te/exchange/hosted/miles/pararallel_lines_and_transversal.ppt
ANNOTATION: This PowerPoint show includes definitions, graphics, sound, and links to help
introduce parallel lines and transversals. Problems specific to the topic are given and solved.
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8. G-8
Geometry Standard 8:
Students know, derive, and solve problems involving the perimeter, circumference, area,
volume, lateral area, and surface area of common geometric figures.
WEBSITE: http://www.ies.co.jp/math/products/geo1/applets/cava/cava.html
ANNOTATION: This site has java applets that demonstrate basic geometry concepts.
This particular applet solves the area of similar quadrilaterals.
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9. G-9
Geometry Standard 9:
Students compute the volumes and surface areas of prisms, pyramids, cylinders, cones,
and spheres; and students commit to memory the formulas for prisms, pyramids, and
cylinders.
WEBSITE: http://www.mathsisfun.com/geometry/solid-geometry.html
ANNOTATION: This site is appropriate for struggling learners needing a basic
overview of solid geometry. The text explanation and graphics are comprehensible and
This lesson explains the properties of solids.
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10. G-10
Geometry Standard 10:
Students compute areas of polygons, including rectangles, scalene triangles, equilateral
triangles, rhombi, parallelograms, and trapezoids.
WEBSITE: http://www.mathwarehouse.com/geometry/quadrilaterals/
ANNOTATION: This site provides graphics and text explanation of quadrilaterals. It is
appropriate for struggling learners. Supplementary worksheets are available on this topic
and other basic geometry concepts.
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11. G-11
Geometry Standard 11:
Students determine how changes in dimensions affect the perimeter, area, and volume of
common geometric figures and solids.
WEBSITE: http://korthalsaltes.com/cuadros.php?type=p
ANNOTATION: This site contains paper models of geometry figures that can be printed
and assembled. It is an excellent resource for tactile learners who will understand the
concepts of perimeter, area and volume of geometric figures by creating the figures.
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12. G-12
Geometry Standard 12:
Students find and use measures of sides and of interior and exterior angles of triangles
and polygons to classify figures and solve problems.
WEBSITE: http://www.mathopenref.com/anglesalternateexterior.html
ANNOTATION: This applet demonstrates the concept that alternate exterior angles are
equal if the lines are parallel. This site also contains an applet to demonstrate the
measure of interior angles.
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13. G-13
Geometry Standard 13:
Students prove relationships between angles in polygons by using properties of
complementary, supplementary, vertical, and exterior angles.
WEBSITE: http://www.math.com/school/subject3/lessons/S3U1L5GL.html
ANNOTATION: This math.com site offers step-by-step text explanation and worksheets
to reinforce basic geometry concepts. This particular activity addresses solving
complementary and supplementary angle relationships. This site is appropriate for
struggling learners.
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14. G-14
Geometry Standard 14:
Students prove the Pythagorean Theorem.
WEBSITE: http://www.pbs.org/wgbh/nova/proof/puzzle/
ANNOTATION: This animation offers an explanation of the Pythagorean theorem that
may be helpful to struggling learners. Shockwave must be loaded on the computer to
view it.
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15. G-15
Geometry Standard 14:
Students prove the Pythagorean Theorem.
WEBSITE: http://nlvm.usu.edu/en/nav/frames_asid_164_g_4_t_3.html?
open=instructions&from=topic_t_3.html
ANNOTATION: This site offers virtual manipulatives to reinforce geometry concepts.
This virtual puzzle demonstrates the Pythagorean theorem. It is appropriate for struggling
learners.
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16. G-16
Geometry Standard 15:
Students use the Pythagorean Theorem to determine distance and find missing lengths of
sides of right triangles.
WEBSITE: http://mathopenref.com/pythagorasproof.html
ANNOTATION: This site offers the opportunity to interact with a graphical proof of the
Pythagorean Theorem. This simulation may be a helpful tool for hands on or visual
learners.
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17. G-17
Geometry Standard 16:
Students perform basic constructions with a straightedge and compass, such as angle
bisectors, perpendicular bisectors, and the line parallel to a given line through a point
off the line.
WEBSITE: http://www.ditutor.com/line/locus_geometry.html
ANNOTATION: This site provides graphics and a text explanation of perpendicular
bisectors. Worksheets are available to print for practice. The search mechanism (buscar)
on this site is in Spanish.
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18. G-1 8
Geometry Standard 17:
Students prove theorems by using coordinate geometry, including the midpoint of a line
segment, the distance formula, and various forms of equations of lines and circles.
WEBSITE: http://www.ck12.org/flexbook/chapter/2272
ANNOTATION: This site is accessed through Ed 1 stop on the Contra Costa County
office of Education site or at the above web address. This excerpt on circles is from an
online geometry book called a flex book. The pages can be printed and collated specific
to standard.
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19. G-19
Geometry Standard 18:
Students know the definitions of the basic trigonometric functions defined by the angles
of a right triangle. They also know and are able to use elementary relationships between
them. For example, tan(x) = sin(x)/cos(x), (sin(x))2 + (cos(x)) 2 = 1.
WEBSITE: http://www.mathsnet.net/graphs/cuta1.html
ANNOTATION: This interactive graphing simulation reinforces the concept of
trigonometric functions. The sine curve can be calculated from the inputted values.
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20. G-20
Geometry Standard 19:
Students use trigonometric functions to solve for an unknown length of a side of a right
triangle, given an angle and a length of a side.
WEBSITE: http://www.saltire.com/applets/triangles/tri1s2a.htm
ANNOTATION: This applet demonstrates the trigonometric function of computing the
lengths of the side of a triangle given the angle and length of a side.
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21. G-21
Geometry Standard 20:
Students know and are able to use angle and side relationships in problems with special
right triangles, such as 30°, 60°, and 90° triangles and 45°, 45°, and 90° triangles.
WEBSITE: http://mathopenref.com/triangle306090.html
ANNOTATION: This site has many interactive animations to demonstrate geometric
concepts. This lesson identifies the importance of the relationship between angles and
proportions.
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22. G-22
Geometry Standard 21:
Students prove and solve problems regarding relationships among chords, secants,
tangents, inscribed angles, and inscribed and circumscribed polygons of circles.
WEBSITE: http://glencoe.mcgraw-hill.com/sites/0078778549/student_view0/chapter10/
lesson6/personal_tutor.html
ANNOTATION: This site is available through curriculum support on ED1 stop on the
Contra Costa County Office of education site or at the web address listed above. This
site is the publisher provided support for the Glencoe Geometry textbook. It is an
excellent resource for chapter assessments, quizzes, work sheets, California standards
practice, read world application problems and the personal tutor seen below.
This particular lesson is a real word application of secants, tangents and angle measures.
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23. G-23
Geometry Standard 22:
Students know the effect of rigid motions on figures in the coordinate plane and space,
including rotations, translations, and reflections.
WEBSITE: http://www.softschools.com/math/geometry/transformations/
ANNOTATION: This site is appropriate for struggling learners and allows the user to
enact a simulation in a video game format to grasp the concepts of reflection, rotation and
transformation.
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