a cylinder vessel without a lid is made from a sheet of metal. Find the area of the metal required if the length of the vessel is 35 cm and it's radius is 14.

4 answers

find the area of the circle base first.
so:
A = πr²
= π(14)²
= 615.7521601
= 615.75 (2d.p.)

then,
SA = 2πr² + 2πrh
= 2(π(14)²) + 2π(14)(35)
= 4310.265121
= 4310.27 (2d.p)

A = 4310.27 - 615.75 (because we don't want to lid)
= 3694.52 (and that should be your answer)

IF YOU WANT A QUICKER WAY:
= πr² + 2πrh
and that should get you the same answer as above.
This is a really good clear, explantion Brea you are a great tutor his helped me too
3696
Circumference= 2πr
=2×(22/7)×14
=88
Area of circle = πr^2
=(22/7)×14×14
=616cm
Area of rectangle= l × B
=88×35
=3080cm^2
Area of metal required is 3080+ 616 = 3696sq.cm