Question

an arc in the form of sem ellipse it is 50m wide and height of 20m how wide is the arc height of 10m above a base?

Answer 1

so, you have semi-axes of 25 and 20. Thus, the ellipse is represented by the equation
x^2/625 + y^2/400 = 1
So, now just find x when y=10, and double it.