2022 AMC 12B Problem 2

Below is the professionally curated solution for Problem 2 of the 2022 AMC 12B, from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 2022 AMC 12B solutions, or check the answer key.

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Concepts:rhombusPythagorean Theoremarea

Difficulty rating: 1020

2.

In rhombus ABCD,ABCD, point PP lies on segment AD\overline{AD} so that BPAD,\overline{BP} \perp \overline{AD}, AP=3,AP = 3, and PD=2.PD = 2. What is the area of ABCD?ABCD? (Note: the figure is not drawn to scale.)

353\sqrt5

1010

656\sqrt5

2020

2525

Solution:

The side length is AD=AP+PD=5,AD = AP + PD = 5, so AB=5.AB = 5. In right triangle APB,APB, BP=AB2AP2=259=4. BP = \sqrt{AB^2 - AP^2} = \sqrt{25 - 9} = 4.

Taking ADAD as the base and BPBP as the height, the area is ADBP=54=20.AD \cdot BP = 5 \cdot 4 = 20.

Thus, the correct answer is D.

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