Math, asked by risu77, 1 year ago

plzzz help meee plzz​

Attachments:

Answers

Answered by rakhithakur
0

Answer:

Step-by-step explanation:

given that

CSA of the cone =423.9

r:l = 3:5

r/l = 3/5

3l = 5r  -------------------------(1)

CSA of cone = 423.9

πrl = 423.9

rl = 423.9×3.14

rl = 1331.046

l = 1331.046/r --------------------(2)

from (1) and (2)

3(1331.046/r) = 5r

3993.138/r = 5r

3993.138 = 5r²

r² = 3993.138/5=798.6276

r = 28.26 cm    (proved)

from (1)

3l = 5(28.26)

3l = 141.3

l = 141.3/3 cm  

  = 47.1

we have on relation between r, h , l.

l = √r²+h²

then

h = √l²-r²

h = √ (47.1)² - (28.26)²

h = √2218.41 - 798.6276

h = √1419.7824

h = 37.68 cm 

so the volume = πr^2*h/3

= 3.14*798.6276*37.68/3= 31512.57027

Similar questions