A Toy in the Form of Cone of Radius 3.5 cm Mounted on a Hemisphere of same Radius. The total Height of the toy is 15.5 cm, find the total Surface area of toy. | Bzziii
A toy in the form of cone of radius 3.5 cm mounted on a hemisphere of same radius. The total height of the toy is 15.5 cm, find the total surface area of toy.
Given,
Radius of cone = 3.5 cm, height of cone = 15.5 – 3.5 = 12 cm
Slant height of cone can be calculated as follows:
`l = \sqrt{h^{2}+r^{2}}`
`l = \sqrt{12^{2}+3.5^{2}}`
`l = \sqrt{144^{2}+12.25^{2}}`
`l = \sqrt{156.25}` = 12.5 cm
Radius of cone = 3.5 cm, height of cone = 15.5 – 3.5 = 12 cm
Slant height of cone can be calculated as follows:
`l = \sqrt{h^{2}+r^{2}}`
`l = \sqrt{12^{2}+3.5^{2}}`
`l = \sqrt{144^{2}+12.25^{2}}`
`l = \sqrt{156.25}` = 12.5 cm
Curved surface area of cone can be calculated as follows:
= `\pi rl`
= `22/7``\times` 3.5 `\times` 12.5
= 137.5 `"cm"^2`
Curved surface area of hemispherical portion can be calculated as follows:
= `2\pi r^2`
= `22/7``\times` 3.5 `\times` 3.5
= 77 `"cm"^2`
Hence, total surface area = 137.5 + 77 = 214.5 `"cm"^2`
= `\pi rl`
= `22/7``\times` 3.5 `\times` 12.5
= 137.5 `"cm"^2`
Curved surface area of hemispherical portion can be calculated as follows:
= `2\pi r^2`
= `22/7``\times` 3.5 `\times` 3.5
= 77 `"cm"^2`
Hence, total surface area = 137.5 + 77 = 214.5 `"cm"^2`
Comments
Post a Comment