In a rectangular trapezoid ABCD, Angle A = 90 degrees, AB side is half the size of CD.

In a rectangular trapezoid ABCD, Angle A = 90 degrees, AB side is half the size of CD. Find the rest of the corners of the trapezoid.

1. Let’s draw from the top С perpendicular СН to the larger base AD.
2. In the resulting rectangle CH = AB.
3. In a right-angled triangle of the СD, the perpendicular to the CH is a leg, half the size of the hypotenuse of the СD. Therefore, the angle D is equal to 30 °.
4. We calculate the value of the DСН angle:
DСН angle = 180 ° – 30 ° – 90 ° = 60 °.
5. We calculate the value of the angle of the ВСD:
ВСD angle = 90 ° + 60 ° = 150 °.
Answer: angle A = 90 °, angle B = 90 °, angle C = 150 °, angle D = 30 °.