Question

Jed Sites

The perimeter of an isosceles triangle is 7x + 5y - 8 units, and the length of the base of the
triangle is x - y - 2 units. What is the length, in units, of each of the congruent sides of the
triangle?
3x + 2y - 5
3x + 3y - 3
4x + 2y - 5
6x + 4y - 10

Answer 1

Option B: 3x + 3y - 3

Explanation:

In an isosceles triangle, the two congruent sides are equal.

We are told the base is; x - y - 2 units

Now let each of the congruent sides be represented as A.

Thus the perimeter equation will be;

P = 2A + x - y - 2

Now, we are told that the perimeter is; 7x + 5y - 8 units

Thus;

7x + 5y - 8 = 2A + x - y - 2

Rearranging gives;

7x - x + 5y + y - 8 + 2 = 2A

2A = 6x + 6y - 6

Divide through by 2 to give;

A = 3x + 3y - 3 units