Answer:
m∠B = 107°
Step-by-step explanation:
The given geometric figure is a deltoid or quadrilateral with two pairs of equal adjacent sides whose diagonals are perpendicular.
The longer diagonal divides two opposite angles into two equal parts, which means:
m∠A = 2 · 32 = 64°
m∠C = 2 · 41 = 82
Also the angles m∠B ≅ m∠D = x
The total sum of the inner angles in the quadrilateral is 360°, which means:
2 · x = 360 - ( 64 + 82) = 360 - 146 = 214 => x = 214/2 = 107°
m∠B = 107°
God with you!!!