2013 AMC 10A Problem 3

Below is the professionally curated solution for Problem 3 of the 2013 AMC 10A, from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 2013 AMC 10A solutions, or check the answer key.

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Concepts:triangle area

Difficulty rating: 770

3.

Square ABCDABCD has side length 10.10. Point EE is on BC,\overline{BC}, and the area of ABE\triangle ABE is 40.40. What is BE?BE?

44

55

66

77

88

Solution:

We have by the formula for the area of a triangle that 40=1210BE. 40 = \dfrac{1}{2} \cdot 10 \cdot BE. This gives us 40=5BE 40 = 5BE BE=8. BE = 8. Thus, E is the correct answer.

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