A rectangular sheet of paper, 44 cm× 20 cm, is rolled along its lengt

1.	A rectangular sheet of paper, 44 cm× 20 cm, is rolled along its length to form a cylinder. Find the total surface area of the cylinder thus generated.
Answer» We have, Dimensions of rectangular sheet of paper = 44cm × 20cm When this sheet of paper is rolled along its length, Circumference of base becomes = 44 cm By using the formula, Circumference of base = 2πr So, 2πr = 44 2 × 22/7 × r = 44 r = 44×7 / 44 = 7cm Radius = 7cm Height = 20 cm ∴ Total surface area of cylinder = 2πr (h+r) = 2 × 22/7 × 7 (20 + 7) = 2 × 22/7 × 7 × 27 = 1188 cm²

A rectangular sheet of paper, 44 cm× 20 cm, is rolled along its length to form a cylinder. Find the total surface area of the cylinder thus generated.

Answer»

We have,

Dimensions of rectangular sheet of paper = 44cm × 20cm

When this sheet of paper is rolled along its length,

Circumference of base becomes = 44 cm

By using the formula,

Circumference of base = 2πr

So, 2πr = 44

2 × 22/7 × r = 44

r = 44×7 / 44

= 7cm

Radius = 7cm

Height = 20 cm

∴ Total surface area of cylinder = 2πr (h+r)

= 2 × 22/7 × 7 (20 + 7)

= 2 × 22/7 × 7 × 27

= 1188 cm²