Question

An arch is in the form of a semi ellipse.it is 50m wide at the base and has ahight of 20m.how wide is the arch at the height of 10m above the base?

Answer 1

since a=25 and b=20, the ellipse can be represented by

x^2/25^2 + y^2/20^2 = 1

Now just find 2x when y=10.

Answer 2

25