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A regular octagon has 8 congruent interior angles. What is the measure of each angle?

 May 19, 2015

Best Answer 

 #2
avatar+5478 
+20

The formula for finding the sum of a polygon's interior angles is 180(n-2), where n is the number of sides/angles.

Thus, for an octagon:

Sum of interior angles = 180(8-2)

= 180(6)

= 1080

 

Since the 8 angles are congruent, simply divide 1080 by 8 for the measure of each angle:

 

1080/8 = 135 degrees

 May 19, 2015
 #1
avatar+128079 
+10

360 / 8 = 45°   for each central angle.....the other two angles of each congruent triangle are 67.5° each

 

 May 19, 2015
 #2
avatar+5478 
+20
Best Answer

The formula for finding the sum of a polygon's interior angles is 180(n-2), where n is the number of sides/angles.

Thus, for an octagon:

Sum of interior angles = 180(8-2)

= 180(6)

= 1080

 

Since the 8 angles are congruent, simply divide 1080 by 8 for the measure of each angle:

 

1080/8 = 135 degrees

kitty<3 May 19, 2015
 #3
avatar+118587 
0

Kitty has done it via formula.  There is nothing wrong with that.  Thanks Kitty.

CPhill hse done it very logically, he just forgot to mention that 2 of his isoscles triangle 'leg' angles adds up to one internal ocatgon angels.  His answer is the same as Kitty's.

I really like how you did that Chris.     

 May 19, 2015

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