High School

8-1: MathXL for School: Practice & Problem Solving

X8.1.PS-13

Reasoning What is the surface area of the cone? Use 3.14 for . Use pencil and

paper. Suppose the diameter and the slant height of a cone are cut in half. How

does this affect the surface area of the cone? Explain.

The surface area of the cone is about cm².

(Do not round until the final answer. Then round to the nearest whole number as needed.)

14 cm

Question Hell

8 cm

(The figure is not drawn to scale)

8 1 MathXL for School Practice Problem Solving X8 1 PS 13 Reasoning What is the surface area of the cone Use 3 14 for

Answer :

The surface area of the cone would be 216. 66 cm².

If the diameter and the slant height of a cone are cut in half, the area would become 1 / 4 of the original area.

How to find the are ?

The area of a cone is:

SA = πr ( r + l )

= 3.14 x 3 x (3 + 20)

= 3.14 x 3 x 23

= 216. 66 cm²

If the slant height and diameter are cut in half :

Diameter new = 6 / 2

= 3 cm

Slant height :

= 20 / 2

= 10 cm

The new area of the cone is:

= 3. 14 x 1. 5 x (1.5 + 10)

= 3.14 x 1. 5 x 11. 5

= 54. 165 cm²

Compared to the old are:

= 54. 165 / 216. 66

= 1 / 4

When you halve the dimensions, the surface area becomes one-fourth of the original.

Find out more on surface area at https://brainly.com/question/30253224

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