Isosceles Triangle Calculator

Area, height and perimeter of an isosceles triangle.

Area 12

Height 3

Perimeter 18

Formula: height = √(leg² − (base/2)²)

Step-by-step with your numbers:

1. Values used:

2. Base = 8

3. Equal side (leg) = 5

5. Area = 12

6. Height = Base - Equal side (leg) = 8 - 5 = 3

7. Perimeter = 18

Did we solve your problem today?

Triangle with two equal sides.

The math behind it

height = √(leg² − (base/2)²); area = ½ × base × height.

Base 8, leg 5 → height 3, area 12.

Valid?

The leg must be more than half the base.