A metal solid made up of a cylindrical bar fixed onto a cube. The cylindrical bar fixed onto a cube. The cylindrical bar is 20 cm long and has a diameter of 7 cm. Each side of the cube is 9 cm long.

Question

The surface of the solid was painted. What area in area in cm2 was painted? (Take π
=22/7 )

Answer 1

area of cube = 6*49
subtract pi (3.5^2)

so cube area painted = 294 - pi(3.5)^2

side area of cylinder = 20 ( 7 pi)
end areas = 2 pi(3.5^2) but delete one
so total cylinder area =140 pi+pi(3.5^2)

total = 294-pi(3.5)^2+140pi+pi(3.5)^2
= 294 + 140 pi
= 294 + 20(22) = 294+440 = 734

Answer 2

area of cube = 6*81
= 486

Answer 3

oh 486 + 440

Answer 4

Open cylinder
Pi3.5^2 =38.5
2pi3.5^2×20= 440
440+38.5= 478.5
Cube
6l^2 = 6×81 = 486
486-38.5 =447.5
447.5 + 486= 926