Curated OER
Mean Twisters - Mean Proportional
In this mean proportional activity, learners work in pairs to solve right triangle problems. They use ratios and proportions of similar triangles to determine a missing length. This two-page activity contains 16 problems.
Curated OER
Proofs of the Pythagorean Theorem
Working individually and collaboratively, geometers gain a clear understanding of the Pythagorean theorem. They create, explain, and compare proofs of the theorem. Proofs involve areas of trapezoids, squares, and triangles, congruent...
Illustrative Mathematics
Find the Change
This exercise is an opportunity for algebra learners to understand the connection between the slope of a line and points found on the line. Use similar triangles to explain why slope m is the same between any two points. Discuss with the...
Big Kid Science
Measuring Shadows Using an Ancient Method
How did ancient peoples determine the height of really tall objects? Young scientists and mathematicians explore the concept of using shadows to measure height in a hands-on experiment. Paired pupils measure shadows, then calculate the...
Curated OER
Similar Figures
In this similar figures learning exercise, students identify corresponding sides and corresponding angles of given polygons. They identify similar figures. This three-page learning exercise contains 18 problems.
Curated OER
Constructing Midsegments of Triangles
Young scholars construct midsegments. In this geometry lesson, students make conjectures and apply properties of triangles to solve problems. They complete an activity on the computer.
Curated OER
Congruent and Similar Figures: Reteach
In this congruent and similar figures worksheet, students review three steps to help them determine if figures are congruent, similar, or neither. Students then study the pairs of shapes and determine if they are congruent, similar, or...
Curated OER
Investigating Trigonometric Ratios Through Similar Right Triangles.
49Students investigate the properties of right triangles. In this geometry lesson, students differentiate between similar and congruent triangles. They use the Pythagorean Theorem to find the missing angles and sides.
Curated OER
Why can't We Use SSA to Prove Triangles Congruent?
Students investigate triangles and congruences. In this geometry lesson, students differentiate between inductive and deductive reasoning. They differentiate between similar and congruent triangles.
Curated OER
Pedal Triangles
Students identify the properties and theorems of triangles. In this geometry lesson plan, students construct angle bisectors using a compass and straight edge. They identify triangular similarity and congruency.
Curated OER
The Minimal Distance Point from the Vertices of a Triangle
Learners calculate the distance from the vertex of a triangle to the center. In this geometry lesson plan, students find the shortest distance between a point and the vertex of a triangle. They relate this concept of distance to the real...
Curated OER
Exploring Characteristics Needed to Prove Two Trianlges Congruent
Tenth graders explore congruent triangles. In this geometry lesson, 10th graders investigate the conditions necessary to prove two triangles congruent. The lesson combines dry erase board activities and the use of technology.
EngageNY
Law of Cosines
Build upon the Pythagorean Theorem with the Law of Cosines. The 10th part of a 16-part series introduces the Law of Cosines. Class members use the the geometric representation of the Pythagorean Theorem to develop a proof of the Law of...
Curated OER
Unit 5: Worksheet 4 - Proportions
In this proportion worksheet, learners use proportions to find the missing side of similar triangles, they identify the percent of a number, and graph points on a coordinate plane. Students solve real life story problems dealing with...
Curated OER
Find the Shape
Students identify points on the coordinate plane using ordered pairs and also plot the ordered pairs on the coordinate plane. They also use properties of shapes to identify polygons such as triangles and quadrilaterals
(square,...
Curated OER
Let the Matrix Do It
Pupils create a matrix of the vertices of a triangle and produce new matrices that dilate, translate, rotate, and reflect the original triangle. After multiplying each matrix by a new scale factor, they graph the new matrix and describe...
101 Questions
Snail's Pace
Time doesn't fly when you're watching a snail cross a sidewalk. Combining the concepts of the Pythagorean Theorem and the distance, rate, and time formula, learners determine how long it takes a snail to go from one corner of a sidewalk...
CK-12 Foundation
Pythagorean Theorem to Determine Distance: Ladders
Young mathematicians to the rescue! Pupils use an interactive to find lengths relating a ladder against a building. The problems involve determining how long a ladder must be to reach a given floor to what floor can a given ladder reach.
Mathalicious
Out of Left Field
A baseball trajectory and a parabola seem to make the best pair in real-world quadratic applications. Here is a current baseball resource with questions, discussions, and explorations regarding a quadratic function and home run...
West Contra Costa Unified School District
Introduction to Trigonometric Functions
Scholars first learn the definitions of the sine ratio, the cosine ratio, and the tangent ratio. After mastering these definitions, they use the new information to solve triangles.
Curated OER
The Greeley, Colorado Problem
In this Greeley, Colorado problem, students read a word problem. They use given directions and a coordinate plane to determine the number of ways to satisfy given travel conditions. This one-page worksheet contains 1 multi-step...
Curated OER
Congruence with Robot Gobot
Students identify the properties of solids and polygons. In this geometry instructional activity, students identify the different measurements of a triangle. They use congruence parts and theorem to prove their answer.
El Paso Community College
Geometry Definitions
Geometry is full of shapes, figures, and corresponding things here and there. The guide shares all of the key pieces of geometric information in a nicely color-coded and labeled sheet.
Curated OER
Shapes from Shapes
Geometric shapes are really cool. Examine triangles, quadrilaterals, trapezoids, rhombuses, parallelograms, pentagons, and hexagons with your class. They draw large shapes and small shapes then compare them to understand their shapely...