Question

What is the rule to find the total surface area and lateral surface area and volume of cylinder​

Answer 1

Answer:

curved surface area is 2pie×radius ×height......a

2 circular surfaces is 2×pie×radius²......b

total area is a+b

Answer 2

FORMULAE :-------

T. S. A {total surface area}

• $2r\pi(r + h)$

Justification :--

Cylinder has Two parts

1. Flat
2. Circular

Circular part when un-folded is like rectangle so, it's area must be lb where l is height of the cylinder and b is the circumference of the flat circle i.e 2πr . so it's area will be 2πrh

Flat part has two congruent Circles so the area of flat part is 2(πr²)

So, it's total surface area is 2πrh+2πr² = 2πr(h+r)

C. S. A {curved surface area}

• $2rh\pi$

Justification:--

Circular part when un-folded is like rectangle so, it's area must be lb where l is height of the cylinder and b is the circumference of the flat circle i.e 2πr . so it's area will be 2πrh

VOLUME

• $2\pi {r}^{2} h$

Justification:--

Volume is cross-section times length . here the cross-section is circular and length is the height of the cylinder so the volume is 2πr²h

Hope it Helps