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
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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.
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