Interior and Exterior Angles (6.1/6.2)

6. 1 Interior Angles in Convex Polygons Essential Question: How can you determine the number of degrees in any polygon?

Angles in a ∆ add to 180 An angle inside a polygon

2 2*180= *180= 540

Sum= (n-2) *180

Has all congruent sides and angles angle= (n-2)*180 n

Sum= (n-2)*180 Angle= (n-2)*180 N A= (9-2)*180 9 A= 1260/9 A= 140

Sum= (n-2)*180 Angle= (n-2)*180 N 1980= (n-2)*180 11=n-2 13=n

Sum= (n-2)*180 Angle= (n-2)*180 N 135 = (n-2)*180 n 135n= (n-2)* n= 180n – n= -360 n=8

5 min Technology Break

6. 2 Exterior Angles in Convex Polygons Essential Question: What is an exterior angle of a polygon?

Angle between side of a polygon and an adjacent side extended outward The sum of the exterior angles of a convex polygon is 360

y=360 y= 360 – 235 y=125

360/7=x = x

Plicker Exit Slip Question 1Question 2 If the sum of the interior angles of a shape is 1620, how many sides does it have? A) 7 B) 9 C) 11 D) 13 The measure of each exterior angle in a pentagon is 2y. Solve for y. A) 2.5 B) 36 C) 54 D) 180

Homework  6.1 evens  6.2 all