Coordinate geometry of rectangles is investigated in this video lesson. The tutorial demonstrates how to use the midpoint, distance, and slope formulas to determine if a quadrilateral is a rectangle on a coordinate plane. [17:26]

Interior and exterior angles of polygons are investigated in this geometry resource. Definitions and video lessons are included.

Explore the interior angles of polygons and the degree of each angle as well as the total degree of the entire polygon. Assess learning with a quiz.

Similar Triangles are explored in this video lesson. Students can check their understanding with an assessment. [5:51]

This video lesson [4:55] describes the characteristics that quadrilaterals and triangles have in common. Students can check their understanding with an assessment.

Determine the value of a variable when solving for the interior angles of a triangle. Check understanding with a quiz.

This video tutorial demonstrates how to find the interior and exterior angles of a triangle.

Special right triangles are explored in this video tutorial. The lesson provides four videos that explain the side ratios for 45-45-90 and 30-60-90 triangles along with real-world examples involving each type of triangle.

If you know the number of sides of a polygon, you can figure out the sum of the interior angles. Take a look at this tutorial to learn how. [6:00]

This tutorial shows you how to use the Triangle Sum Theorem to find the interior angle measurements of a given triangle. [5:09]

This tutorial demonstrates how to create an equation and solve it to find the missing measurements in a quadrilateral. [4:13]

Students explore the interior angles of a polygon by explanding on the concept that a triangle has 180 degrees and developing a formula for all polygons.

This lesson will provide practice problems that involve solving for unknown angle and side measures of equilateral triangles. It is 4 of 5 in the series titled "Equilateral Triangle Interior Angles Practice Problems."

This lesson provides practice problems that involve the sum of the interior angles of triangles. It is 4 of 6 in the series titled "Triangle Interior Angles Practice."

This lesson provides practice problems that involve the sum of the interior angles of triangles. It is 6 of 6 in the series titled "Triangle Interior Angles Practice."

This lesson demonstrates how to use triangles to determine the sum of the interior angles of a polygon. It is 2 of 5 in the series titled "Using Triangles to Find the Sum of Interior Angles."

This lesson demonstrates how to use triangles to determine the sum of the interior angles of a polygon.

This lesson demonstrates how to use triangles to determine the sum of the interior angles of a polygon. It is 3 of 5 in the series titled "Using Triangles to Find the Sum of Interior Angles."

This lesson demonstrates how to use triangles to determine the sum of the interior angles of a polygon.

This lesson demonstrates how to use triangles to determine the sum of the interior angles of a polygon. It is 4 of 5 in the series titled "Using Triangles to Find the Sum of Interior Angles."

This lesson demonstrates how to use triangles to determine the sum of the interior angles of a polygon.

This lesson demonstrates how to use triangles to determine the sum of the interior angles of a polygon.

This lesson will provide practice problems that involve solving for unknown angle and side measures of equilateral triangles. It is 2 of 5 in the series titled "Equilateral Triangle Interior Angles Practice Problems."

This lesson will provide practice problems that involve solving for unknown angle and side measures of equilateral triangles. It is 3 of 5 in the series titled "Equilateral Triangle Interior Angles Practice Problems."