SOLUTION:
We are to find the measure of an interior angle of a regular decagon.
A decagon is a plane figure with ten straight sides and angles.
To find the sum of interior angles in a decagon;
(n - 2) x 180 (where n = 10)
(10 - 2) x 180
= 8 x 180
= 1440 degrees
The measure of an interior angle of a regular decagon is;
1440 / 10
144 degrees