On an aerial photograph, the surface of a pond appears as circular region of 7/16 radius inch. If a distance of 1 inch on the photograph corresponds to an actual distance of 2 miles, which of the following is the closest estimate of the actual surface area of the pond, in square miles?
A. 1.3
B. 2.4
C. 3.0
D. 3.8
E. 5.0
答案给的是B,但是我怎么算出来是A呀, 我的解法是: 3.14*(7/16)^2^2=1.3
这样不对吗?
比例尺给的是距离的比例,算的时候一定要先把距离换算成实际长度再计算面积
如果先计算面积再根据比例尺换算那么就需要把比例尺平方
不知能否说明白
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