All triangles have some things in common. Using these properties of triangles, learners find missing angle measures. Scholars use the Angle Sum Property and properties of special triangles throughout the instructional activity.

Get out those protractors! Geometers measure interior and exterior angles of 10 polygons, including a 24-gon. They also calculate the interior angle sum of the polygons. 

For this angle sum worksheet, students find missing angles of 20 triangles and quadrilaterals.  Students find the missing angle in each polygon by using the total degrees of each and given angle measures.

Your visual geometry learners will appreciate triangle drawings as they model the triangle sum theorem and algebraically solve to find the missing interior angle in a triangle. Practice problems increase in complexity and vary in their...

In this TAKS online math quiz worksheet, students take an online quiz focused angle measurement with a protractor. Quiz can be graded online by clicking a link.

In this angle measures worksheet, students solve six word problems where they are given 6 different polygons, some of which are complex, and must determine angle measures in order to arrive at a solution.

This a fun problem for young geometers to play with while gaining important insight into deductive reasoning. Some will find the answers very quickly, others might take a less direct path, but all will use their knowledge of the sum of...

Learners address 14 questions that include naming all pairs of opposite and supplementary angles for sets of intersecting lines and then, finding the measure of the unknown angle. They determine the measure of the angle that is...

A series of geometry worksheets have mathematicians constructing, dissecting, overlapping, and measuring as they analyze angles in various contexts. Learners use symmetry and reflections in a compass rose to write instructions on...

How can learners use algebra to solve a geometry problem? Help learners create an equation that shows the relationship between the number of sides of a polygon and the sum of the interior angles. Students are asked to divide the...

The Pythagorean Theorem is a staple of middle school geometry. Scholars first investigate angle relationships, both in triangles and in parallel lines with a transversal, before proving and applying the Pythagorean Theorem.

In this angle sum and difference worksheet, 11th graders solve 10 different problems related to determining the angle sum and difference of numbers. First, they determine the exact value of sine and cosine degrees. Then, students utilize...

An informative lesson contains a brief explanation of how the sum of the angles of a triangle is a line. The lesson continues with determining the missing angle in a triangle, or solving for a variable. Using the sum of the...

Show your class that finding angle measures is a regular calculation with a resource that provides 12 problems dealing with the measures of angles in regular polygons. Pupils use formulas for the sum of measures of angles in a polygon to...

This short video show viewers how to connect the sum of the angles in a triangle to other angle measurements. Pupils determine the missing measures for angles involved with triangles and quadrilaterals. Class members then must explain...

How does the number of sides of a polygon affect the angle measures? Learners recognize a pattern in finding the total measure of interior and exterior angles and the number of diagonals. They use the patterns to calculate...

This one activity requires young geometers to pull together information they are currently learning with things they have learned previously. Here they rely on understanding something about parallel lines, alternative interior angles,...

In this geometry worksheet, 10th graders determine if a polygon is convex or concave and apply the polygon Angle sum theorem and the polygon exterior angle sum theorem to determine the measures of interior and exterior angles of a...

Need practice deriving trigonometric angle formulas? With this worksheet, pupils derive the sum and difference formulas for cosine and tangent and the difference formula for sine. Scholars use the sine sum formula and other known...

Polygons — it's all about the angles. Groups work with dynamic geometry software to find the sum of the measures of the angles of various polygons. After finding the information for several polygons, the groups generate a formula that...

Viewers are presented with seven problems with parallel lines and angle relationships and must use the given information to find the measures of specific angles. To finish, they explain their process in finding the measures in the...

Math whizzes work with angle sums and exterior angles to figure out the measure of other angles. This particular publication provides comprehensive support in the form of an anticipatory activity, questions designed to prompt discussion,...

In this polygons worksheet, students fill out a graphic organizer about the name of the polygon, the number of sides, the angle sums, and more. Students complete this for 5 polygons.

For this triangle worksheet set, 9th graders find the relationship between the exterior and remote interior angles in triangles. They determine the formula, and apply it in 15 problems. They use a compass as needed to measure angles.