how can one find it's area?
The same area formula can also be derived from Heron's formula for the area of a triangle from its three sides.
Isosceles triangle
The same area formula can also be derived from Heron's formula for the area of a triangle from its three sides. 
an isosceles triangle has two sides of equal length UNANSWERABLE how did it gat the name? "Isosceles" is made from the Greek roots "isos" (equal) and "skelos" (leg).
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Isosceles triangle [SEP] Area
The area formula_5 of an isosceles triangle can be derived from the formula for its height, and from the general formula for the area of a triangle as half the product of base and height: The same area formula can also be derived from Heron's formula for the area of a triangle from its three sides. However, applying Heron's formula directly can be numerically unstable for isosceles triangles with very sharp angles, because of the near-cancellation between the semiperimeter and side length in those triangles. If the apex angle formula_7 and leg lengths formula_8 of an isosceles triangle are known, then the area of that triangle is: This is a special case of the general formula for the area of a triangle as half the product of two sides times the sine of the included angle.