Question

A regular decagon is shown with isosceles triangles drawn within.
What is one way you could find the measure of the exterior angle of the figure?

Add all the angles in the triangle together to get 180˚.

Add the base angles of the isosceles triangle together to determine the measure of the angle.

Find the measure of the non-base angle of the isosceles triangle which is congruent to the angle.

Subtract the base angles of the triangles from the interior angle measure