Find the lateral area of this cone. Leave your answer in terms of 7.
3 cm
4cm
LA = [ ? ]7 cm2
Hint: Lateral Area of a Cone = mre
Where e = slant height

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