4.6 Quadrilateral
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.MultipleIntelligences
- Divide this lesson into two parts. The first part is going to focus on finding the sum of interior angles of
polygons. The second part is going to focus on finding the sum of the interior angles of a quadrilateral. - Define convex.
- Define polygon.
- Define interior angles.
- Note that the number of interior angles matches the number of sides of the polygon.
- Show how to use the Triangle Sum Theorem to divide the polygon into triangles.
- Demonstrate using an equation to solve for the sum of the measure of the interior angles.
- Have students do this with two new polygons in their notebooks- a pentagon and a decagon.
- Allow time for students to share their work when finished.
- Be sure student answers were found using the equation.
- Part 2 – move onto quadrilaterals
- Test out the equation with a rectangle and a trapezoid.
- Intelligences- logical- mathematical, visual- spatial, interpersonal, intrapersonal
III.SpecialNeeds/Modifications
- Define all terms on the board. Request that students copy these notes into their notebooks.
- Here are the steps to solving these problems.
- Divide the figure into triangles.
- Use an equation to find the sum of the angles.
- With a quadrilateral- check does the sum equal 360◦?
IV.AlternativeAssessment
- Check student work. Be sure that the students are writing an equation when solving for the sum of the interior
angles of both polygons and quadrilaterals. - Provide correction when necessary.
Exterior Angles
I.SectionObjectives
4.6. Quadrilateral