Answer:
LA = 20π cm²
Explanation:
Given the following data;
Radius, r = 4 cm
Height = 3 cm
To find the lateral area (LA) of a cone;
First of all, we would determine the slant height by applying Pythagorean' theorem.
Hypotenuse² = opposite² + adjacent²
Where;
Hypotenuse is the slant height.
Opposite is the height of the cone.
Adjacent is the radius of the cone.
Substituting into the expression, we have;
l² = 3² + 4²
l² = 9 + 16
l² = 25
Taking the square root of both sides, we have;
l = √25
l = 5 cm
Next, we find the LA using the formula;
LA = πrl
Where;
r is the radius of the cone.
l is the slant height of the cone.
Substituting into the formula, we have;
LA = 4 * 5 * π
LA = 20π cm²
