Question

A solid is made up of a cube and a hemisphere attached on its top . Each edge of the cube measure 5 cm and the hemisphere has a diameter of 4.2 cm. Find the total area to be painted.

Answer 1

Heya !!


Edge of cube = 5 cm.

Total surface area of the cube = 6 × Edge² = (6×5×5) = 150 cm².




Area to be painted = ( Total surface area of the cube ) - ( Base area of the hemisphere ) + (Curved surface area of the hemisphere).



=> ( 150 - πr² + 2πr² ) cm²


=> ( 150 + πr² ) cm²



=> ( 150 + 22/7 + 21 * 21 )


=> (150 + 693/50 ) cm².


=> ( 150 + 13.86 ) cm².



=> 163.86 cm².

Answer 2

Answer:

Edge of cube = 5 cm.

Total surface area of the cube = 6 × Edge² = (6×5×5) = 150 cm².

Area to be painted = ( Total surface area of the cube ) - ( Base area of the hemisphere ) + (Curved surface area of the hemisphere).

=> ( 150 - πr² + 2πr² ) cm²

=> ( 150 + πr² ) cm²

=> ( 150 + 22/7 + 21 * 21 )

=> (150 + 693/50 ) cm²

=> ( 150 + 13.86 ) cm².

=> 163.86 cm².