In quadrilateral ABCD m < A= 90°
m 2 C = 50° and m < B = m D.
Find the degree measure of < B.

Answer:
m∠B = 170°
Step-by-step explanation:
Sum of all angles in quadrilateral is 360°:
m∠A + m∠B + m∠C + m∠D = 360°
m∠B = 360° - m∠A - m∠C - m∠D
m∠A = 90°
m∠B = m∠D= 50°
m∠B = 360° - 90° - 50° - 50° = 170°