Question

The sides of an equilateral triangle measure 0.2(10x+90)cm each. If the perimeter of the triangle is 612.6 cm, what is the side length?

Write the equation to solve the problem.


Solve for x


Find the side of the triangle

Answer 1

204.2 cm

Explanation:

equilateral means all sides are of equal length.

the perimeter of such a triangle is simply 3 times one of these sides.

so,

612.6 = 3×0.2×(10x + 90) = 0.6×(10x+90) = 6x + 54

6x = 558.6

x = 93.1

so, a single side is

0.2×(10×93.1 +90) = 0.2×(931 + 90) = 0.2×1021 = 204.2 cm

to check

3×204.2 = 612.6 = the original perimeter.

so, correct.