Answer:
The value of a is 15.
Step-by-step explanation:
First, you have to find the total interior angles of the polygon using the formula, sum = (n-2)×180°, where n represents the number of sides :
sum = (n-2)×180°
sum = (5-2)×180°
sum = 540°
Given that the sum of the interior angle is 540° so in order to find the value of a, you have to add up all the angles in terms of a :
3a + 150 + 8a + 6a + 9a = 540
26a + 150 = 540
26a = 390
a = 390 ÷ 26
a = 15