Find the measure of ∠BEC.
A) 10°
B) 60°
C) 80°
D) 100°

C) 80°

Step-by-step explanation:

8x + (4x + 60) = 180

Supplementary angles

12x + 60 = 180

12x = 120

x = 10

Angle GEC: 4(10) + 60 = 100

Angle BEC = 180 - 100 = 80

(Supplementary angles)

supplementary angles.

answer:   x = 3 + √11     and     x = 3 - √11

step-by-step explanation:

x² - 6x + 9 = 11

(x - 3)² = 11

x - 3 = ±√11

    x = 3 ± √11

x = 3 + √11     and     x = 3 - √11

m∠a is 90°

m∠b is 40°