Question

The length of the base of an isosceles triangle is x. The length of a leg is 3x

- 7. The perimeter of the triangle is 63. Find x. *
20
22
11
12

Answer 1

Option C: 11 is the correct answer.

Explanation:

Given that:

Length of base of isosceles triangle = b = x

The length of leg of triangle = a = 3x-7

Perimeter of triangle = 63

Perimeter of an isosceles triangle is given by

Perimeter = 2a + b

Putting values in the formula

63 = 2(3x-7) + x

63 = 6x-14+x

63 = 7x-14

63+14=7x-14+14

77=7x

7x=77

Dividing both sides by 7

`(7x)/(7)=(77)/(7)\\x=11`

The value of x is 11.

Hence,

Option C: 11 is the correct answer.