SOLUTION: find the area of equilateral triangle whose perimeter is 12 inches.

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Question 663673: find the area of equilateral triangle whose perimeter is 12 inches.
Answer by ReadingBoosters(3246) About Me  (Show Source):
You can put this solution on YOUR website!
Equilateral means all the sides are the same
p = a+b+c or in this case 3s
12 = 3s
s = 4 in for each side
...
To find the height, cut the triangle in half to create two right triangles.
The bottom of one of the triangles is 4/2 = 2
The hypotenuse of the right triangle is 4
solve for the other side, is solving for height
s^2 + 2^2 = 4^2
Isolate s^2
s^2 = 4^2 - 2^2
s^2 = 16-4 = 12
s^2 = 12
sqrt%28s%29+=+sqrt%2812%29
s = sqrt%284%2A3%29
s = 2sqrt%283%29
...
a = 1/2(b)(h)
a = 1/2(4)(2sqrt%283%29)
a = 2(2sqrt%283%29)
a = 4sqrt%283%29
.....
Alternatively,
The area formula in an equilateral triangle is
a=%28s%5E2sqrt%283%29%29%2F%284%29
Plug in the side determined from the perimeter
a=%284%5E2sqrt%283%29%29%2F%284%29
Such that,
a=4sqrt%283%29
.........................
Delighted to help.
-Reading Boosters
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