Question

The figure below shows AB = 2 units and BD = 5 units.
If the area of triangle ADE is 70 square units, what is the area of the trapezoid BCED?
Answer

5.71 square units

7.53 square units

58.80 square units

64.29 square units

Answer 1

i know i need to subtract triangle ABC from he whole but how do i find the area of the triangle with just one dimension

Answer 2

use similarity... the dimensions of the smaller triangle is 2/7 that of the bigger triangle.
since the big triangle a has an area of 70, the smaller triangle has area =(1/2)*(2/7*b)(2/7*h) = 4/49*1/2*bh = 4/49 the area of the big triangle = 5.71.
to get the area of the trapezoid just take that area from the area of the big triangle (70)

Answer 3

thank-you!! you are a life saver my parents don't remember any math they learned in hs and i've never been good at it so im really trying to finish this geometry up before 10 tonight -__-