Question

What is the area of a trapezoid ABCD with bases AB and CD

, if:
AB = 10 cm, BC=DA=13 cm, CD=20 cm;

Answer 1

A= a+b/2h =10+20/2 x13 =195

I believe 195 is correct if not, I’m so sorry

Answer 2

If you draw a perpendicular to CD from point A or point B, you will create a right triangle with one leg 5 and hypotenuse (BC or DA) 13. The other leg of this triangle is the height of the trapezoid:

... h = √(13² -5²) = 12

The area is this height multiplied by the average base length:

... Area = (12 cm)×(10 cm +20 cm )/2 = 180 cm²