Solve the Problem $20 \mathrm{ft}$ On Each Side $4 \mathrm{ft}$ And a Base Of

Multiple Choice

Solve the problem.
-A yard in the shape of a square measures $20 \mathrm{ft}$ on each side. A triangular area with a height of $4 \mathrm{ft}$ and a base of $10 \mathrm{ft}$ is dug up for a flower bed. How much yard area is left over?

A) $180 \mathrm{ft}^{2}$
B) $380 \mathrm{ft}^{2}$
C) $360 \mathrm{ft}^{2}$
D) $420 \mathrm{ft}^{2}$