Find the length of the cone.

slant height= 13cm
radius= 10cm

To find the length of the cone, we can use the Pythagorean theorem. The slant height is the hypotenuse of a right triangle, with the radius as one leg. Let's call the length of the cone "l".

Using the Pythagorean theorem:
l^2 = r^2 + h^2

Substituting the given values:
l^2 = 10^2 + 13^2
l^2 = 100 + 169
l^2 = 269

Taking the square root of both sides, we find:
l ≈ 16.38 cm

Therefore, the length of the cone is approximately 16.38 cm.