The measure of one angle of an octagon is twice that of the other seven angles. What is the measure of each angle?

1 Answer
May 5, 2018

One angle is 240 degrees while the other seven angles are 120 degrees. Here's why:

Explanation:

Sum of interior angles of an octagon: 1080

7 angles with measure "x"
1 angle that's twice "x", 2x

2x + x + x + x + x + x + x + x = 1080

Combine like terms.

9x = 1080

Divide by 9 to isolate for x.

#1080/9# = #120# , so x = #120#

Angle 1: 2(120) = 240
Angle 2: 120
Angle 3: 120
Angle 4: 120
Angle 5: 120
Angle 6: 120
Angle 7: 120
Angle 8: 120