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.