Hello, Jammix!

Divide a triangle in two equal areas by the line parallel to its base.The large triangle has base and heightCode:- * : *: * : * :h * H * : * : * * * * * * * : * b * - * * * * * * * * * * B

The small triangle has base and height

We want: .

From similar triangles: .

Substitute into [1]: .

Therefore: .