In trapezium ABCD there are bases of AD and BC. Angle A is 37 °, angle C is 65 °.

In trapezium ABCD there are bases of AD and BC. Angle A is 37 °, angle C is 65 °. Find the rest of the corners of the trapezoid.

Angles A and B and angles C and D are internal one-sided with parallel lines AD and BC (base of the trapezoid) and secants AB and CD. 180 ° is the sum of internal one-sided angles with parallel straight lines and a secant, we find the missing angles of this trapezoid:
∠ B = 180 ° – ∠ A = 180 ° – 37 = 143 °.
∠ D = 180 ° – ∠ C = 180 ° – 65 ° = 115 °.
Answer: the degree measure of angle B is 143 °, angle D is 115 °.