Question

The first side of a triangle measures 4 in. less than the second side, the third side is 3 in. more than the first side, and the perimeter is 15 in. How long is the third side? If s represents the length of the second side, which of the following represents the length of the third side? s - 4 s - 1 s + 3

Answer 1

Side 1=4 side 2=4 side 3=7

Answer 2

The expression which represents the third side of the triangle is:

s-1

The length of the third side of the triangle is:

17/3 inches.

Explanation:

It is given that:

The first side of a triangle measures 4 in. less than the second side, the third side is 3 in. more than the first side, and the perimeter is 15 in.

If s represents the length of the second side.

Then the first side of the triangle is: s-4

and the third side of the triangle is given by: 3+(s-4)

=3+s-4

= s-4+3

= s-1

Hence, the third side of the triangle is represented by: s-1

Also, the Perimeter of the triangle is: 15 in.

We know that the perimeter is the sum of the length of all the outer boundaries of a figure.

i.e.

(s-4)+s+(s-1)=15

i.e.

s-4+s+s-1=15

s+s+s-4-1=15

3s-5=15

3s=15+5

3s=20

s=20/3 in.

Hence, the third side is given by: (20/3)-1= 17/3 inches.