Answer:
∠ 1 = 36°
Explanation:
Supplementary angles sum to 180° then
∠ 2 + ∠ 3 = 180° , that is
∠ 2 + 126° = 180° ( subtract 126° from both sides )
∠ 2 = 54°
Complementary angles sum to 90° , then
∠ 1 + ∠ 2 = 90° , that is
∠ 1 + 54° = 90° ( subtract 54° from both sides )
∠ 1 = 36°