Question

Find the area of an isosceles triangle in which base is 24 cm and each of equal sides is 13 cm.

Answer 1

Given:

Base = 24 cm

Each equal side = 13 cm

Step-wise calculation:

1. Drop the altitude from the apex to the midpoint of the base.

Half the base = `24/2`

= 12 cm

2. In the right triangle formed, height h satisfies:

`h = sqrt(13^2 - 12^2)`

= `sqrt(169 - 144)`

= `sqrt(25)`

= 5 cm

3. Area = `1/2` × base × height 

= `1/2` × 24 × 5

= 12 × 5

= 60 cm²