Workers plan to apply a reflective coating of paint to one s

Workers plan to apply a reflective coating of paint to one surface of an equilateral triangular shaped highway sign. How many square inches of coating need to be applied to the sign if one side of the triangle is 13 inches?

Solution

coating need to be applied to the sign = area of equiateral triangkle with side 13 inches

area of equiateral triangkle with side a is A= (3 /4)a²

given a=13 in

A= (3 /4)13²

A= 73.2 in²

73.2 square inches of coating need to be applied to the sign if one side of the triangle is 13 inches