Hello, pocketasian!

Are you forgetting the "half" in: . ?

Find the area of an isosceles triangle with two sides of length and one side of lengthCode:A o /|\ / | \ / | \ 2x / | \ 2x / |h \ / | \ / | \ B o-------o-------o C ½x M ½x : - - - x - - - :

We have isosceles triangle with

. . and

is the midpoint of

is the altitude (height} of

In either of the right triangles: .

. .

The base of the triangle is: .

Therefore: .