What is the area of an equilateral triangle whose perimeter is 48 inches?

1 Answer
Aug 5, 2018

Answer: #64sqrt(3)# #"in"^2#

Explanation:

Consider the formula for the area of an equilateral triangle:
#(s^2sqrt(3))/4#, where #s# is the side length (this can be easily proved by considering the 30-60-90 triangles within an equilateral triangle; this proof will be left as an exercise for the reader)

Since we are given that the perimeter of the equilateral trangle is #48# inches, we know that the side length is #48/3=16# inches.

Now, we can simply plug this value into the formula:
#(s^2sqrt(3))/4=((16)^2sqrt(3))/4#

Canceling, a #4# from the numerator and the denominator, we have:
#=(16*4)sqrt(3)#
#=64sqrt(3)# #"in"^(2)#, which is our final answer.