# Area of an isosceles triangle

An isosceles triangle is a triangle in which the two sides are equal in length. Equal sides are called lateral, and the last unequal side is called the base. If a triangle has two equal sides, then these sides are called sides, and the third side is called the base. The angle formed by the sides is called the vertex angle, and the corners, one of the sides of which is the base, are called the corners at the base.

.### Calculation of the area through the base and one side

**Side a:**

**Base of an isosceles triangle b:**

Formula for calculating the area of an isosceles triangle through the base and one side:

### Calculation of area through base and height

**Base of triangle b:**

**Height of triangle h:**

Formula for calculating the area of an isosceles triangle through the base and height:

### Area calculation through side and angle

**Base a:**

**Angle between equal sides @:**

Formula for calculating the area of an isosceles triangle through one side and angle:

### Calculation of area through base and angle

**Base b:**

**Angle α:**

Formula for calculating the area of an isosceles triangle through the base and angle: