If you can in any of these? you (:

12. The sum of the measures of the exterior angles of any polygon, 1 per vertex, is 360.

360 - 261 = 99

99 deg.

13. The sum of the measures of the exterior angles of any polygon, 1 per vertex, is 360.
Here we deal with two regular polygons, so all the exterior angles of each polygon are congruent.

5-gon: 360/5 = 72
7-gon: 360/7 = 51.4...

less than

14. Read again the first statement in the answers of the two problems above.
It makes no difference how many sides a polygon has. The sum of the measures of the exterior angle, one per vertex, is ALWAYS 360.

equal to

15. Answer is d. (n - 2)180

16. b. 360

17. You have a pentagon, a 5-sided polygon, a 5-gon.
The sum of the measures of the interior angles of an n-gon is

(n - 2)180, so for a pentagon, which is a 5-gon, you have

(5 - 2)180 = 3 * 180 = 540

Your pentagon is not regular since not all angles have the same measure.
Since you are given the measures of 4 of the 5 angles, and you know the sum of the measures of all 5 angles, we can find the measure of the missing angle.

104 + 118 + 96 + 115 = 433

Subtract that from 540 to find the measure of the angle:

540 - 433 = 107

The interior angle near A measures 107.

An exterior angle is supplementary to its adjacent interior angle.
The measure of an exterior angle plus the measure of the adjacent interior angle equals 180.
If you subtract the measure of the interior angle from 180, you get the measure of the exterior angle.

A = 180 - 107 = 63

c. 63