Question

find the total surface area of a cone, if it's slant height is 9 m and the radius of its base is 12 m​

Answer 1

Step-by-step explanation:

slant height (l) = 9 m

radius (r) = 12m

1. total surface area (TSA) = π rl + π r*2

= π r ( l+ r)

=22/7×12( 9 + 12)

=22/7×12(21)

=22×12×3

=792m*2

Answer 2

Given

• Slant height of cone=9m
• Radius of cone=12m

To Find

• Total surface area of cone=?

Solution

We have the height and radius of cone

therefore we directly put values in the formula to get our answer.

Here we have

Slant height (l)=9m

Radius of base (r)=12m

Putting values we get

$\rm \: tsa \: of \: cone = \pi r(l + r) \\ \\ \implies \rm \: tsa = \frac{22}{7} \times 12(9 + 12) \\ \\ \implies \rm \boxed{ \bf tsa = 792 \: {m}^{2} } \: \: \: \: \: \: \: \:$

So the tsa of cone is 792m²

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