Example 3 : Savitri had to make a model of a cylindrical kaleidoscope

1.	Example 3 : Savitri had to make a model of a cylindrical kaleidoscope for her scienceproject. She wanted to use chart paper to make the curved surface of the kaleidoscope(see Fig 13.10). What would be the area of chart paper required by her, if she wanted
Answer» Radius of the base of the cylindrical kaleidoscope (r) = 3.5 cm. Height (length) of kaleidoscope (h) = 25 cm. Area of chart paper required = curved surface area of the kaleidoscope = 2πrh =2×22/7×3.5× 25 cm2 = 550 cm^2

Example 3 : Savitri had to make a model of a cylindrical kaleidoscope for her scienceproject. She wanted to use chart paper to make the curved surface of the kaleidoscope(see Fig 13.10). What would be the area of chart paper required by her, if she wanted

Answer»

Radius of the base of the cylindrical kaleidoscope (r) = 3.5 cm.

Height (length) of kaleidoscope (h) = 25 cm.

Area of chart paper required = curved surface area of the kaleidoscope

= 2πrh

=2×22/7×3.5× 25 cm2

= 550 cm^2