13. what is the value of the missing angle (first picture)
1. 50°
2.60°
3.100°
4.240°
~
14. what is the value of the missing angle? (second picture)
1.129°
2.153°
3.169°
4.720°

13) You have:

 1. To calculate the sum of the interior angles of a polygon, you must apply the following formula:

 (n-2)180°

 2. So, you have:

 (5-2)180°=540°

 3. Therefore:

 x+150°+150°+90°+90°=540°
 x=540°-150°-150°-90°-90°
 x=60°

 14) 1. You must apply the formula for calculate the sum of the interior angles of a polygon:

 (n-2)180°
 (6-2)180°=720°

 2. Then, you have:

 x+75°+151°+75°+115°+135°=720°
 x=169°