What is the area of quadrilateral ABCD?

The length of AB is 9, BC is 5, CD is 12, and AD is 10. When angle BCD is 90 degrees, what is the area of quadrilateral ABCD? #sat #act #trigonometric #math #sine #cosine #digitalsat

[@LuisdeBritoCamacho]

BD^2 = 25 + 144 = 169 ; BD = 13
Triangle [BCD] Area = (5 * 12) / 2 = 30
Triangle [ABD] Area (using Heron's Formula for : 9 / 10 / 13) = 44,9 ~ 45
Quadrilateral Area = 30 + 45 = 75 Square Units (approx.)

[@JacekiElzbietaWojutynscy]

Error: triangle ABD (9,10,13) is not a right triangle.
It should be rectangular.

[@JacekiElzbietaWojutynscy]

Error: triangle ABD (9,10,13) is not a right triangle.
It should be rectangular.