## anonymous 5 years ago the surface area of a cone that has a true height of 11 inches and the base has a radius of 4.5 inches.

the formula for the surface area of a cone is $\pi R \sqrt{R^2+H^2}$ where R is radius and H is height. If by true height you mean length of the side, use trigonometric functions (or pythagorean theorem) to find the height of the cone.