Difference between revisions of "2021 Fall AMC 12A Problems/Problem 21"
(→Solution) |
(→Solution) |
||
Line 42: | Line 42: | ||
~NH14 | ~NH14 | ||
+ | |||
+ | ==See Also== | ||
+ | |||
+ | {{AMC12 box|year=2021 Fall|ab=A|num-b=20|num-a=22}} |
Revision as of 21:38, 23 November 2021
Problem
Let be an isosceles trapezoid with
and
. Points
and
lie on diagonal
with
between
and
, as shown in the figure. Suppose
,
,
, and
. What is the area of
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
See Also
2021 Fall AMC 12A (Problems • Answer Key • Resources) | |
Preceded by Problem 20 |
Followed by Problem 22 |
1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 • 16 • 17 • 18 • 19 • 20 • 21 • 22 • 23 • 24 • 25 | |
All AMC 12 Problems and Solutions |