2021 AMC 10B Fall Problem 2

Below is the professionally curated solution for Problem 2 of the 2021 AMC 10B Fall, from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 2021 AMC 10B Fall solutions, or check the answer key.

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Concepts:area decomposition triangle area

Difficulty rating: 560

What is the area of the shaded figure shown below?

$4$

$6$

$8$

$10$

$12$

Solution:

The area is a triangle of area $\dfrac {4\cdot 5}2 - \dfrac{2\cdot 4}2 = 10-4$ $= 6$ since we subtract the area of a smaller triangle from a larger triangle.

Thus, the answer is B .

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