Question

19
Slant height of the cone is 20 cm and
it's perpendicular height is 16 cm.
Find its base radius. *
(2 Points)
12
8​

Answer 1

Answer:

12 cm

Step-by-step explanation:

Given -

Slant height of cone (l) = 20 cm

Perpendicular height (h) = 16 cm

To find -

Base radius (r) of cone

Solution -

As we know that

l² = h²+r²

so

r² = l²-h² or

r = √(l²-h²)

so

r = √(20²-16²)

= √(400-256)

= √144

= 12

Hence base radius of cone = 12 cm

hope it helps.

Answer 2

Given:

✰ Slant height of the cone = 20 cm

✰ Perpendicular height of the cone = 16 cm

To find:

✠ Base radius of the cone.

Solution:

Let the right-angled triangle ABC be revolved around its side AB to form a cone; then AB is the perpendicular height ( h ) of the cone formed BC is the radius ( r ) of its base and AC is its slant height ( l ).

Clearly, l² = h² + r².

We have used Pythagoras theorem above. So, we will put the values in the given equation above and then doing the required calculations, we will find out the radius of the base of cone.

✭ l² = h² + r² ✭

Putting the values, we have:

➤ 20² = 16² + r²

➤ 400 = 256 + r²

➤ r² = 400 - 256

➤ r² = 144

➤ r = √144

➤ r = 12 cm

∴ The base radius of of the cone = 12 cm

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