Question

the curved surface area of right circular cone is 12320 cm2. if it's radius is 56cm .find its slant height

with explain on formate
only 1 marks question
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Answer 1

Answer:

42 cm

Step-by-step explanation:

Radius of the cone ( r ) = 56 cm

Let the height = h cm

Slant height = l cm

CSA of the cone = 12320 cm²

π rl = 12320

( 22/7 ) × 56 × l = 12320

l = ( 12320 × 7 ) / ( 56 × 22 )

l = 70 cm

l² = r² + h²

h² = l² - r²

= 70² - 56²

= ( 70 + 56 ) ( 70 - 56 )

= 126 × 14

= 14 × 3 × 3 × 14

h = √ ( 14 × 14 ) × ( 3 × 3 )

h = 14 × 3

h = 42 cm