What is the area of the poster board that she has left

Find the area of the parallelogram, find the area of the triangle, then subtract the triangle's area from the area of the parallelogram.

Area of Parallelogram:
A= base * height
A= 20 in * 10 in
A= 200 in^2

Area of Triangle:
A= 1/2 base * height
A= 1/2 (10 in)(9 in)
A= 1/2 (90)
A= 45 in ^2

Area of Poster Left:
subtract the difference
A= Parallelogram Area - Triangle Area
A= 200 in^2 - 45 in^2
A= 155 in^2

ANSWER: 155 in^2 is the area of the poster board she has left.

Hope this helps! :)

Your answer will be

The answer simplified would be. -6300x