Question

what is ( mangle abc )?
( circ ) ( mangle abc = 15^circ )
( circ ) ( mangle abc = 45^circ )
( circ ) ( mangle abc = 60^circ )
( circ ) ( mangle abc = 75^circ )

Explanation:

Step1: Identify angles at A and C

∠BAC = 75°, ∠ACB = 180° - 135° = 45°

Step2: Calculate ∠ABC

Sum of triangle angles = 180°, so ∠ABC = 180° - 75° - 45° = 60°

Answer:

B. m∠ABC = 60°