Question

The perimeter of a triangle is 51cm the lengths of its side are x cm, x+2 cm, and x+4 cm. What is the length, in cm, of the longest side of the triangle

Answer 1

Given:

Sides of a triangle are x cm, x+2 cm, and x+4 cm.

Perimeter of triangle is 51 cm.

To find:

The the length of the longest side of the triangle.

Solution:

Sides of a triangle are x cm, x+2 cm, x+4 cm and perimeter of the triangle is 51 cm.

Perimeter of a triangle is the sum of all sides of the triangle.

`x+(x+2)+(x+4)=51`

`3x+6=51`

`3x=51-6`

`3x=45`

Divide both sides by 3.

`x=15`

Now, length of sides of the triangle are

`x=15\text{ cm}`

`x+2=15+2=17\text{ cm}`

`x+4=15+4=19\text{ cm}`

Therefore, the length of longest side of the triangle is 19 cm.