Question

14.The base of an isosceles triangle is 4/5 of one of its equal sides. The perimeter of the triangle is 420 cm. Determine the lengths of its sides.​

Answer 1

Given:-

• The base of an isosceles triangle is 4/5 of one of its equal sides.
• Perimeter of triangle is 420 cm

Find:-

Length of isosceles triangle.

Solution:-

Let the -

• length of isosceles triangle be x cm.

According to question,

$\underline{\boxed{\rm{\bold{Perimeter \:of\:triangle \:=\:Sum\:of\:it's \:sides}}}}$

Substitute the known values in above formula

=> x + x + 4x/5 = 420

=> (5x + 5x + 4x)/5 = 420

=> (14x)/5 = 420

=> 14x = 420(5)

=> 14x = 2100

=> x = 150

•°• Length of isosceles triangle is 150 cm.

Answer 2

Answer:

Suppose the length of the Isosceles triangle will be = x .

• Substitute the value by using it's formula:

x + x + 4x /5 = 420.

(5x + 5x + 4x )/5 = 420.

(14x )/5 = 420.

14x = 420(5).

14x = 2100.

x = 150.

The length of an isosceles triangle equals to 150 cm .