Question

form a circle of radius 15 cm is a sector with angle to 216 degrees is cut out and its bonding radii are bent so as to form a cone find its volume​

Answer 1

hey mate!

v = πr²h/3 .

What is needed to be found are values of ' r ' & ' h '.

' r ' is the radius of the base. ' s ' is the slant length that is the radius (R=15cm) of the sector with 216° angle (I hope it is ° though you didn't mention it).

The sectoral arc becomes the perimeter of the base circle.

2πr = (216/360)[2πR]

=> r/R = 216/360

r = 15 X (216/360)

= 216/24 = 9 cm.

And h² = s² - r² . . . {Pythagoras theorem}

= 15² - 9² = 3²(5² - 3²) = 3²(4²) = 12²

h = 12 .

Substitute the values of r, h and get V.