Angles in Polygons - PowerPoint PPT Presentation

1 / 8
About This Presentation
Title:

Angles in Polygons

Description:

Finding the Number of Sides of a Regular Polygon Given Interior Angle ... Then, you subtract it from 180 to get the exterior angle. ... – PowerPoint PPT presentation

Number of Views:279
Avg rating:3.0/5.0
Slides: 9
Provided by: matthe234
Category:
Tags: angle | angles | polygons

less

Transcript and Presenter's Notes

Title: Angles in Polygons


1
Angles in Polygons
  • 3.6
  • Matt, James, Eric, Robert

2
Sum of Interior Angles of a Polygon
  • The sum of the measures of the interior angles of
    a polygon with n sides is 180(n-2)
  • N the number of sides the polygon has.
  • Ex. Triangle has 3 sides, so 180(3-2) 180(1)
    180 º which is the sum of the interior angles of
    the triangle

3
Interior Angle of a Regular Polygon Formula
  • 180(n-2)/n
  • Ex. A square has 4 sides, so 180(4-2)/4 360/4
    90º

4
Sum of Exterior Angles of a Polygon
  • The sum of the measures of the exterior angles of
    a polygon is 360 º
  • Ex. In a equilateral triangle, each exterior
    angle is 120 º. 120120120 360 º

120 º
120 º
120 º
5
Finding the Number of Sides of a Regular Polygon
Given Interior Angle
  • First, you need one of the interior angles.
  • Then, you subtract it from 180 to get the
    exterior angle.
  • When you get the exterior angle you divide 360 by
    it and your answer should be the number of sides
    the polygon has.
  • Ex. I.A.60, 180-60120, 360/1203 sides

6
Finding the Number of sides of a Regular Polygon
Given Exterior Angle
  • First, you need one of the exterior angles.
  • Then, you divide 360 by it
  • The answer should be the number of sides the
    polygon has.
  • Ex. E.A.90, 360/904 sides

7
Finding the Measure of an Angle of a Polygon
Given the Angle Measures as Mathematical
Expressions
  • First, combine the like terms of all the
    expressions.
  • Then, find out the sum of all the interior
    angles.
  • After this is done, all you do is the algebra and
    find out what the x equals.
  • Then you plug x into each problem.

8
Example
4x3x2xx 360 10x 360 10x/10360/10 X 36
4(36) 144
3(36) 108
4x
3x
2x
x
2(36) 72
1(36) 36
Write a Comment
User Comments (0)
About PowerShow.com