The area of the base of the cone is 64π square millimeters, and the area of the lateral surface is 112π square millimeters. Find the radius r and slant height ℓ of the cone.

Respuesta :

Answer:

Radius = 8 mm

Slant Height = 14 mm

Step-by-step explanation:

Base of a cone is a circle.

Area of circle is given as [tex]A=\pi r^{2}[/tex]

Where [tex]r[/tex] is the radius.

Given that

[tex]A = 64 \pi\ mm^2\\\Rightarrow \pi r^{2} = 64\pi \\\Rightarrow r^{2} = 64\\\Rightarrow r = 8\ mm[/tex]

Hence, radius is 8 mm.

Formula for Lateral Surface Area of a cone:

[tex]LSA = \pi rl[/tex]

Where [tex]r[/tex] is the radius and

[tex]l[/tex] is the slant height of cone

Given that [tex]LSA = 112 \pi\ mm^2[/tex]

[tex]\Rightarrow 112\pi = \pi \times 8 \times l\\\Rightarrow 8 \times l = 112\\\Rightarrow l = 14\ mm[/tex]

Hence, slant height is 14 mm

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