Reporting Category Geometry

Quadrilaterals

Reporting category Geometry

Overview Students explore characteristics of triangles and quadrilaterals and discover the sum of the measures of the angles of triangles and quadrilaterals.

Related Standard of Learning 6.14

Objective

· The student will identify the sum of the measures of the angles of any triangle or quadrilateral.

Materials needed

· A copy of the “Quadrilaterals” worksheet for each student

Instructional activity

1. Review the proper procedure for measuring angles.

2. Have students draw any type of triangle. Ask students to measure the interior angles of their triangle and to determine the sum. (180°)

3. Allow students to share their results, leading them to understand that the sum of the angles of any triangle is 180°.

4. Draw a picture of a square on the board or overhead. Ask students to identify the shape.

5. Demonstrate to students how to divide the square into two triangles.

6. Ask students whether they could use what they know about the sum of the angles of a triangle to figure out the sum of the angles of a square. Allow students to share their ideas, leading them to realize that the sum of the angles of a square is 360°.

7. Ask students to predict if all quadrilaterals would have the same angles sum. Have students write their predictions along with an explanation.

8. Distribute the “Quadrilaterals” worksheet. to students, and have them identify each shape based on its attributes.

9. Explain to students they will use the sheet to find the measures of the angles.

10. Allow students to work with a partner to complete the worksheet.

11. Once the worksheet is completed, have students revisit their predictions to determine if they were correct.

12. Allow students to share their results.

13. Have students complete a journal entry on quadrilaterals, including types, descriptions of each type, and finding the sum of the measures of the angles of a quadrilateral. Ask them to include in their entry an easy way to always remember that the sum of the measures of the angles of a quadrilateral is 360°.

Sample assessment

· Informally assess students as they complete the activity.

· Use the journal entry as a formal assessment.

Quadrilaterals

Name: Date:

Divide each quadrilateral into triangles and determine the sum of the measures of the angles of each quadrilateral. Record the results on the space provided.

1. Name of quadrilateral: ______