An equilateral triangle has the same area as a circle with circumference 100. To the nearest tenth, give the sidelength of the triangle.

An equilateral triangle has the same area as a circle with circumference 100. To the nearest tenth, give the sidelength of the triangle.
A. 42.9
B. 60.6
C. 269.4
D. 47.4
E. 67.1

Correct Answer: A
Explanation/Reference:
Explanation:
The circle with circumference 100 has radius

Its area is
A = πr²
A = π×




We can substitute this for A in the equation for the area of an equilateral triangle, and solve for s:




s ≈ √1,837.76 ≈ 42.9
The correct response is 42.9.

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