Question

find the total surface area of cone ,if it's slant height is 9dm and diameter of its base 24 dm​

Answer 1

Answer:

Step-by-step explanation:

Total surface are of cone having base radius r and slant height L is

( πr² ) + π × × L

Exp :-

r = 24 / 2 = 12dm

L = 9dm

=>

π ( 12 )² + π × 12 × 9

=>

π ×12 { 12 + 9 }

=>

π ×12 { 21 }

=>

( 22 / 7 ) × 12 × 21

=>

22 × 12 × 3

= 792dm²

1 dm = ( 1 / 10 )m

=>

1 dm² = ( 1 / 10² )m²

=>

792dm² = 792 / 10² m²

= 7.92m²