AMC10 2008 B
AMC10 2008 B · Q7
AMC10 2008 B · Q7. It mainly tests Triangles (properties), Area & perimeter.
An equilateral triangle of side length 10 is completely filled in by non-overlapping equilateral triangles of side length 1. How many small triangles are required?
一个边长为 10 的等边三角形完全被不重叠的边长为 1 的等边小三角形填充。需要多少个小三角形？
(A)
10
10
(B)
25
25
(C)
100
100
(D)
250
250
(E)
1000
1000
Answer
Correct choice: (C)
正确答案：（C）
Solution
The side length of the large triangle is 10 times the side length of each small triangle, so the area of the large triangle is $10^2 = 100$ times the area of each small triangle.
大三角形的边长是每个小三角形边长的 10 倍，因此大三角形的面积是每个小三角形面积的 $10^2 = 100$ 倍。
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