Me with this geometry problem !

Check the picture below.

bearing in mind the "slant height" is 0.51 meters, since there are 100 cm in 1 meter, then in 0.51m there are 0.51*100 or 51 cm.

13,328.73

To find this, first you need to find the radius which can be found through the pythagorean theorem set up as so:

24^2 + b^2 = .51^2

This gets you 44.45cm.

You then plug this in to the surface area equation of a cone which is:

SA = pi x radius (radius + square root of h^2 + r^2 unsquare root)

SA = pi x 44.45cm ( 44.45cm + square root of 25cm^2 + 44.45cm^2 unsquare root)

SA = 13,328.73cm^2

Hope this helps!

The answer would be 24mm