SOLUTION: ABCD is a trapezium with right angles at B and C, AB=5cm DC=12cm and the area of the trapezium is 34cm. Calculate ADC. Show diagram

Algebra ->  Parallelograms -> SOLUTION: ABCD is a trapezium with right angles at B and C, AB=5cm DC=12cm and the area of the trapezium is 34cm. Calculate ADC. Show diagram      Log On


   



Question 1135106: ABCD is a trapezium with right angles at B and C, AB=5cm DC=12cm and the area of the trapezium is 34cm. Calculate ADC. Show diagram
Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


The instruction "calculate ADC" is very poorly stated, and not clear. The only interpretation that seems to make sense is it means "determine the measure of angle ADC". So I will assume that is the question....

Here is a diagram: right angles at B and C; AB=5 and DC=12.

I've added point E on DC to make ABCE a rectangle.



The area of the trapezoid, 34, is the height, BC, times the average of the tow bases, AB and CD. Given AB=5 and CD=12, the height of the trapezoid is 4.

With AB=CE=5 and CD=12, DE=7; then with AE=BC=4, the measure of angle ADC is

arctan%284%2F7%29