Interior angles are the angles inside a shape. In the context of geometry, interior angles are the angles formed between two sides of a polygon. The sum of the interior angles of a polygon depends on the number of sides the polygon has.

The formula to find the sum of the interior angles of a polygon is:

Sum of interior angles = (n - 2) * 180°

where n is the number of sides of the polygon.

To find the measure of each individual interior angle of a regular polygon, you can use the formula:

Measure of each interior angle = Sum of interior angles / number of sides

For example, in a regular hexagon (a polygon with 6 sides), the sum of the interior angles would be (6 - 2) * 180° = 4 * 180° = 720°. To find the measure of each interior angle, you would divide the sum of the interior angles by the number of sides: 720° / 6 = 120°.

- Understand the concept of interior angles and how they relate to polygons.
- Learn the formula for finding the sum of the interior angles of a polygon: (n - 2) * 180°.
- Practice finding the measure of each individual interior angle using the formula: Sum of interior angles / number of sides.
- Work on identifying the interior angles of different polygons and calculating their measures.

Study GuideSimilarity and scale Worksheet/Answer key

Similarity and scale Worksheet/Answer key

Similarity and scale Worksheet/Answer key

Similarity and scale Worksheet/Answer keyUsing Similar Polygons Worksheet/Answer keySimilar Polygons Worksheet/Answer keyUsing Similar Polygons Worksheet/Answer keySimilar Polygons

Number and Operations (NCTM)

Understand numbers, ways of representing numbers, relationships among numbers, and number systems.

Understand and use ratios and proportions to represent quantitative relationships.

Compute fluently and make reasonable estimates.

Develop, analyze, and explain methods for solving problems involving proportions, such as scaling and finding equivalent ratios.

Geometry (NCTM)

Analyze characteristics and properties of two- and three-dimensional geometric shapes and develop mathematical arguments about geometric relationships.

Understand relationships among the angles, side lengths, perimeters, areas, and volumes of similar objects.

Create and critique inductive and deductive arguments concerning geometric ideas and relationships, such as congruence, similarity, and the Pythagorean relationship.

Apply transformations and use symmetry to analyze mathematical situations.

Describe sizes, positions, and orientations of shapes under informal transformations such as flips, turns, slides, and scaling.

Measurement (NCTM)

Apply appropriate techniques, tools, and formulas to determine measurements.

Solve problems involving scale factors, using ratio and proportion.

Grade 8 Curriculum Focal Points (NCTM)

Geometry and Measurement: Analyzing two- and three-dimensional space and figures by using distance and angle

Students use fundamental facts about distance and angles to describe and analyze figures and situations in two- and three-dimensional space and to solve problems, including those with multiple steps. They prove that particular configurations of lines give rise to similar triangles because of the congruent angles created when a transversal cuts parallel lines. Students apply this reasoning about similar triangles to solve a variety of problems, including those that ask them to find heights and distances. They use facts about the angles that are created when a transversal cuts parallel lines to explain why the sum of the measures of the angles in a triangle is 180 degrees, and they apply this fact about triangles to find unknown measures of angles. Students explain why the Pythagorean Theorem is valid by using a variety of methods - for example, by decomposing a square in two different ways. They apply the Pythagorean Theorem to find distances between points in the Cartesian coordinate plane to measure lengths and analyze polygons and polyhedra.