2021 Fall AMC 12A Problems/Problem 21
Solution
First realize that Thus, because
we can say that
and
From the Pythagorean Theorem, we have
and
Because
from the problem statement, we have that
Solving, gives
To find the area of the trapezoid, we can compute the area of
and add it to the area of
Thus the area of the trapezoid is
Thus the answer is
~NH14