Hello

I want to calculate the area under the length "L" of this shape.

W, h and b are known.

I am using the formula for a ellipse, pi*h*L/4 but it is not so good when h gets bigger for instance or when b gets smaller.

When h is small, the calculated area with the elipse equation gets to big, and when h gets larger the calculated area get smaller than it really is..

Any ideas or tips ?