Answer:
The sum of the interior angle measures of a regular decagon is 1440°
Explanation:
Given a regular decagon.
we have to find the sum of the interior angle measures of a regular decagon.
The sum of all of the interior angles using the formula

where n is the number of sides.
For regular decagon, n=10
The sum of all of the interior angles


Hence, the sum of the interior angle measures of a regular decagon is 1440°