Determine the measures of interior and exterior angles of polygons, justifying the method used.
Remarks
Example 1: Calculate the measure of one interior angle and one exterior of a regular octagon. Explain your method.Example 2: Suppose that you will make a picture frame like the one shown below. To make the regular hexagonal frame, you will use identical trapezoidal pieces. What are the measures of the angles of the trapezoids? Explain your answer.

General Information
Subject Area: X-Mathematics (former standards - 2008)
Grade: 912
Body of Knowledge: Geometry
Idea: Level 2: Basic Application of Skills & Concepts
Standard: Polygons - Identify and describe polygons (triangles, quadrilaterals, pentagons, hexagons, etc.), using terms such as regular, convex, and concave. Find measures of angles, sides, perimeters, and areas of polygons, justifying the methods used. Apply transformations to polygons. Relate geometry to algebra by using coordinate geometry to determine transformations. Use algebraic reasoning to determine congruence, similarity, and symmetry. Create and verify tessellations of the plane using polygons.
Date Adopted or Revised: 09/07
Content Complexity Rating:
Level 2: Basic Application of Skills & Concepts
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More Information
Date of Last Rating: 06/07
Status: State Board Approved - Archived
Assessed: Yes
Test Item Specifications
-
Item Type(s):
This benchmark may be assessed using:
MC
,
FR
item(s)
- Clarification :
Students will determine the measures of interior and exterior angles of polygons. - Content Limits :
All angle measurements will be in degrees. - Stimulus Attributes :
Items may be set in either real-world or mathematical contexts.
Graphics should be used in these items, as appropriate.
Sample Test Items (2)
- Test Item #: Sample Item 1
- Question:
A regular hexagon and a regular heptagon share one side, as shown in the diagram below.
Which of the following is closest to the measure of x, the angle formed by one side of the hexagon and one side of the heptagon?
- Difficulty: N/A
- Type: MC: Multiple Choice
- Test Item #: Sample Item 2
- Question:
Claire is drawing a regular polygon. She has drawn two of the sides with an interior angle of 140°, as shown below.
When Claire completes the regular polygon, what should be the sum, in degrees, of the measures of the interior angles?
- Difficulty: N/A
- Type: FR: Fill-in Response
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