单选题
In the preceding figure, each of the four squares has sides of length 2x. If triangle PQR is formed by joining the centers of three of the squares, what is the perimeter of triangle PQR in terms of x?
【正确答案】
D
【答案解析】You are given that the length of each side of the square is 2x. Because triangle PQR is formed by joining the centers of the squares, the length of sides PQ and QR is also 2x. To find the length of PR, use the Pythagorean theorem, which states that a2+b2=c2, where c is the hypotenuse (PR):
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The perimeter is equal to the distance around the triangle, so add the lengths of the sides:
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The perimeter is equal to the distance around the triangle, so add the lengths of the sides:
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