Answer:
shape is a Pentagon (has 5 sides)
Sum of interior angles is 540°
x = 90°
m∠B = 90°
m∠E = 100°
Step-by-step explanation:
to find the sum of the interior angles you take the number of sides, deduct two, and multiply by 180
a 5-sided figure would be (n - 2)·180° = 3(180) = 540°
add together all five angle measures and set equal to 540; combine like terms and solve for 'x'
220 + 130 + 130 + x + x + 10 = 540
350 + 2x + 10 = 540
2x + 360 = 540
2x = 180
x = 90
