If you have the net of cone (excluding a circular base).
So it is a sector of a circle, with the radius given.
Can you work out the would be height of the circle by doing -
exterior sector angle / 360 = x
x times diameter of circle = answer
Just wondering if someone could proof it.. using perhaps a different cyclinder to the one below?
(dont need question answering, but thats where the idea comes from)
You are given the radius [call it R] and the interior angle, thus you can compute the arc lengh AB.
The arc length AB becomes the circumference of the base of the cone, then you can compute the radius of the base of the cone [call it r].
You already know the slant distance (the distance from a point on the circumference of the cone to the apex) of the cone.
The height of the cone =