Question

question 1-1
find the surface area of the cone. leave your answer in terms of π.
24 mm
14 mm
585π mm²
532π mm²
224π mm²
217π mm²

Explanation:

Step1: Find the radius

The diameter is 14 mm, so the radius $r=\frac{14}{2}=7$ mm.

Step2: Recall the slant - height

The slant - height $l = 24$ mm.

Step3: Use the surface - area formula

The surface area of a cone $A=\pi r(r + l)$. Substitute $r = 7$ mm and $l=24$ mm into the formula: $A=\pi\times7\times(7 + 24)=\pi\times7\times31 = 217\pi$ $mm^{2}$.

Answer:

$217\pi$ $mm^{2}$