Exercise 19 Page 818

We are asked to find the lateral area and surface area of the given cylinder.

We will do these things one at a time.

Lateral area

Let's recall the formula for the lateral area L of a right cylinder. L=2π rh Here, r is the radius of the base, and h is the height of the cylinder. Since we are given that the radius is 3mm and the height is 15 mm, we can substitute them into the formula and calculate L.

The lateral area of the cylinder is 90 π mm^2 that is approximately 282.7mm^2.

Surface Area

Let's recall the formula for the surface area of a cylinder. S=L+2π r^2 In this formula, r is the radius of the base and L is the lateral area of the cylinder. Substituting r with 3 and L with 90 π into the formula, we can calculate S. Let's do it!

The surface area of the cylinder is about 339.3 mm^2.