Question
a cylinder of wooden block has base radius 'r' cm height 'h' cm and a total surface area of 32pi cm^2
1)show that r^2+hr=16
2)given that its height is 4cm more than its base radius, find the value of 'r' and of 'h'
1)show that r^2+hr=16
2)given that its height is 4cm more than its base radius, find the value of 'r' and of 'h'
Answers
Steve
the surface area is 2πr^2 + 2πrh
= 2π(r^2+hr)
Now it's clear that r^2+hr=16...
Now, using h=r+4, you have
2πr(r+r+4) = 32π
= 2π(r^2+hr)
Now it's clear that r^2+hr=16...
Now, using h=r+4, you have
2πr(r+r+4) = 32π