Curated OER
Tennis Triangle
Students calculate the height of a tree or flagpole. They measure the shadow of the tree or flagpole and the length of a shadow of a meterstick. Using similar triangles, calculate the heigh. Devise two additional ways in which to measure...
Curated OER
Easy Worksheet: Types of Triangles
In this types of triangles worksheet, students solve 6 short answer problems. Students identify the type of triangle being described according to side length or angle measure.
Curated OER
Proofs with Triangles
In this geometry worksheet, high schoolers prove triangle congruence by making statements with reasons and concluding with the AAS or HL theorem. There are 2 proofs.
Math Mammoth
Angles in a Triangle 2
Youngsters draw specified angles when given measurements of other angles and discover traits of angles in similar triangles. This one-page worksheet contains six multi-step problems.
Curated OER
Group Isomorphisms
Students identify and apply properties of triangles. In this geometry lesson, students define equilateral triangles by sides and angles. They build cardboard triangles as they study properties of triangles.
Curated OER
Proofs
In this geometric proof learning exercise, students compose 20 triangle congruency proofs. Students will decide if there is enough information in problems 1-6 to prove if any triangles are congruent. In problems 17 to 20, students use...
Curated OER
2-D polygons
A hands-on activity uses the Zome modeling system, and helps young geometers either learn or review their knowledge of polygons. Students build as many different 2-dimensional polygons as possible: triangle, square, rectangle, pentagon,...
Curated OER
Calculating the shortest distance between two points
Eighth graders find the length of the third side of a right triangle.
Curated OER
Sine
In this sine worksheet, 10th graders solve 10 different problems by determining the sine in each right triangle shown. They determine the sine of one point by applying the other points given in the problem.
Discovery Education
Exploring Geometry
Middle schoolers construct a three-dimensional model of a city using both similar and congruent figures and geometric transformations. City must have at least ten buildings with each building labeled and may be constructed out of paper...
Shodor Education Foundation
Pythagorean Theorem
Most adults remember learning about the Pythagorean theorem, but they don't all remember how to use it. The emphasis here is on developing an intuitive understanding of how and when to use the theorem. Young mathematicians explore...
EngageNY
Lines That Pass Through Regions
Good things happen when algebra and geometry get together! Continue the exploration of coordinate geometry in the third lesson in the series. Pupils explore linear equations and describe the points of intersection with a given polygon as...
EngageNY
Using Trigonometry to Determine Area
What do you do when you don't think you have enough information? You look for another way to do the problem! Pupils combine what they know about finding the area of a triangle and trigonometry to determine triangle area when they don't...
EngageNY
Between-Figure and Within-Figure Ratios
Tie the unit together and see concepts click in your young mathematicians' minds. Scholars apply the properties of similar triangles to find heights of objects. They concentrate on the proportions built with known measures and solve to...
EngageNY
Applications of the Pythagorean Theorem
Begin seeing the world through the lens of geometry! Use the 19th installment in a 25-part module to apply the Pythagorean Theorem to solve real-world problems. Individuals sketch situations resulting in right triangles such as the...
Illustrative Mathematics
Tilt of Earth's Axis and the Four Seasons
Geometry meets earth science as high schoolers investigate the cause and features of the four seasons. The effects of Earth's axis tilt features prominently, along with both the rotation of the earth about the axis and its orbit...
Curated OER
Pythagorean Theorem
Students identify a right angle and right triangle. They perform WebQuests searching for similar figures and solve for the length of one of the sides given the other two.
Illustrative Mathematics
Tangent to a Circle From a Point
Learners see application of construction techniques in a short but sophisticated problem. Combining the properties of inscribed triangles with tangent lines and radii makes a nice bridge between units, a way of using...
Curated OER
Perimeter and Area
In this perimeter and area activity, 6th graders find the perimeter and area of different right triangles. Students complete 9 problems total.
Lone Star College
Geometry Worksheet II
Young geometers get practice with the algebra of angles in an extensive skills practice worksheet. Supplementary, complementary, and vertical angle relationships are used, along with parallel lines cut by a transversal and angle sum...
Curated OER
Geometry Worksheet: Right Triangle
In this geometry worksheet, 10th graders apply their knowledge of altitudes and geometric mean to solve the right triangle in order to find the length of the hypotenuse. The one page worksheet contains one problem. Answers...
EngageNY
Trigonometry and the Pythagorean Theorem
Ancient Egyptians sure knew their trigonometry! Pupils learn how the pyramid architects applied right triangle trigonometry. When comparing the Pythagorean theorem to the trigonometric ratios, they learn an important connection that...
Illustrative Mathematics
Converse of the Pythagorean Theorem
Use the given tasks and detailed teacher's commentary to introduce your 8th graders to the Pythagorean theorem and its converse. Embedded links to information about Egyptian geometry make your presentation interesting. Consider...
EngageNY
Finding Systems of Inequalities That Describe Triangular and Rectangular Regions
How do you build a polygon from an inequality? An engaging lesson challenges pupils to do just that. Building from the previous lesson in this series, learners write systems of inequalities to model rectangles, triangles, and even...