Since ST = TR, let's let x = each length


Also, let's say the parallelogram has height h


So, the length of the parallelogram's base = x + x = 2x
Area of a PARALLELOGRAM = (base)(height)
= (2x)(h)
= 2xh


Now let's determine the area of triangle QST

Area of any triangle = (base)(height)/2
So, area of triangle QST = xh/2

What is the ratio of the area of triangle QST to the area of the parallelogram?
Answer = xh/2 : 2xh

Looks like we need to simplify our ratio.
Take: xh/2 : 2xh
Divide both sides by xh to get: 1/2 : 2_
Multiply both sides by 2 to get: 1 : 4

Answer: C

Cheers,
Brent