To find the slant height, we can use the Pythagorean Theorem. The Pythagorean Theorem states that in a right triangle, the square of the hypotenuse is equal to the sum of the squares of the other two sides.
In this case, the height of the cone is the perpendicular side, the radius (half of the diameter) is the base side, and the slant height is the hypotenuse.
From the image, we know that the diameter is 13 cm, so the radius is 13/2 = 6.5 cm.
Let's label the height as h, the slant height as L, and the radius as r.
Using the Pythagorean Theorem, we have:
L^2 = r^2 + h^2
L^2 = 6.5^2 + 6^2
L^2 = 42.25 + 36
L^2 = 78.25
Taking the square root of both sides, we get:
L = 8.8 cm
Therefore, the slant height must be approximately 8.8 cm.