3.6 Quadrilaterals
Interior Angles
I.SectionObjectives
- Identify the interior angles of convex polygons.
- Find the sums of interior angles in convex polygons.
- Identify the special properties of interior angles in convex quadrilaterals.
II.Cross-curricular-Mandalas
- Use the following image to discuss interior angles of quadrilaterals.
- This is Figure 06.01.01
- http://www.isibrno.cz/ gott/mandala/sriclr2.gif
- This is an image of a mandala that is composed of triangles that can also be interpreted to be quadrilaterals.
- You can use this image to discuss the measure of the interior angles of the quadrilateral with students.
- Show them how two triangles can be combined together to become a quadrilateral.
- Then remind students that the interior angles of a triangle add up to be 180◦according to the Triangle Sum
Theorem. - Then ask the students to look at how many degrees are in a quadrilateral based on the fact that it is made up
of two triangles. - The students will conclude that it is equal to 360◦.
III.TechnologyIntegration
- Have students complete some research on mandalas.
- Where do they come from?
- When were they first used?
- What is the purpose of a mandala?
- Have students keep a record of the websites that they visit.
- Allow time for students to share their findings.
IV.NotesonAssessment
- Assessment is completed through student discussion.
- Listen to the students as they share their thoughts and ideas.
- Be sure that they understand how the interior angles of a quadrilateral are equal to 360◦.
Exterior Angles
I.SectionObjectives
Chapter 3. Geometry TE - Enrichment