Question

he isosceles triangle has a perimeter of 7.5 m. Which equation can be used to find the value of x if the shortest side, y, measures 2.1 m?

Answer 1

2x+ 2.1 = 7.5

x=2.7

Explanation:

The perimeter of an isosceles triangle with sides x and y is

2x+y = P

I put y as the single side since the question said y is the shortest side. It should say shorter sides if the two sides with the same length are smaller than the third.

We know y =2.1 and P = 7.5

Substituting these values in, we get

2x+ 2.1 = 7.5

Subtract 2.1 from each side

2x+2.1 -2.1 = 7.5 -2.1

2x= 5.4

Divide each side by 2

2x/2 = 5.4/2

x = 2.7 m