Answer:
see explanation
Step-by-step explanation:
(a)
∠ XBC = 55° because it corresponds to ∠ AXY
(b)
since XB = XC then Δ XBC is isosceles with base angles congruent, that is
∠ XBC = ∠ XCB = 55°
the sum of the 3 angles in Δ XBC = 180° , then
∠ BXC + 55° + 55° = 180°
∠ XBC + 110° =180° ( subtract 110° from both sides )
∠ XBC = 70°
