Answer:
1. S.A of a cone = 565.56 cm².
2. S.A of a cone = 276.496 cm².
3. S.A of a sphere = 128.696 cm².
4. S.A of a sphere = 113.112 cm².
Step-by-step explanation:
Given the following data;
1. Radius, r = 15cm
Slant height, l = 12cm
Mathematically, the surface area of a cone is given by the formula;
Surface area of a cone = πrl
Substituting into the formula, we have;
S.A of a cone = 3.142 * 15 * 12
S.A of a cone = 3.142 * 180
S.A of a cone = 565.56 cm²
2. Radius, r = 8cm
Slant height, l = 11cm
Surface area of a cone = πrl
S.A of a cone = 3.142 * 8 * 11
S.A of a cone = 3.142 * 88
S.A of a cone = 276.496 cm²
3. Radius, r = 3.2 cm
Mathematically, the surface area of a sphere is given by the formula;
Surface area of a sphere = 4πr²
Substituting into the formula, we have;
S.A of a sphere = 4 * 3.142 * 3.2²
S.A of a sphere = 4 * 3.142 * 10.24
S.A of a sphere = 40.96 * 3.142
S.A of a sphere = 128.696 cm²
4. Diameter, d = 6cm
Radius, r = diameter/2 = 6/2 = 3 cm
Surface area of a sphere = 4πr²
S.A of a sphere = 4 * 3.142 * 3²
S.A of a sphere = 4 * 3.142 * 9
S.A of a sphere = 36 * 3.142
S.A of a sphere = 113.112 cm²
