Question

A wooden toy rocket is in the shape of a cone mounted on a cylinder, as shown in fig. The height of the entire rocket is $26cm,$ while the height of the conical part is $6cm.$ The base of the conical portion has a diameter of $5cm,$ while the base diameter of the cylindrical portion is $3cm.$ If the conical portion is to be painted orange and the cylindrical portion yellow, find the area of the rocket painted with each of these colours. (Take $\pi =3.14$ )

Answer 1

b'The height of cone is $6cm$

The radius of cone is $2.5cm$

The slant height is given as $\sqrt{{2.5}^2+6^2}\sqrt{6.25+36}\sqrt{42.25}=6.5$

The Surface area of cone is $\pi rl\pi 5\times 6.5=32.5\pi$

Area of base is $\pi R^2-\pi r^2\pi ({2.5}^2-{1.5}^2)\pi (6.25-2.25)=4\pi$

The area that is painted with orange is $32.5\pi +4\pi =36.5\pi c{m}^2$

The height of cylinder $20cm$

The radius of cylinder $1.5cm$

The curved surface area is $\pi rh\pi \left(1.5times20\right)=30\pi$

Area of base is $\pi {1.5}^2=2.25\pi$

The area that is painted with Yellow is $30\pi +2.25\pi =32.25\pi c{m}^2$

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