Question

A toy is in the shape of cylinder surmounted by a cone. The radius of cylinder is 20cm and heights of cylindrical and conical portions are 4.2cm and 2.1cm respectively. Find the volume of the toy.

Answer 1

Height of the cylindrical part =13cm
Radius of cone , cylinder and hemi sphere=5cm
r=5cm for hemisphere cylinder and cone.
Height of cone h=30−5−13=12
The area of canvas required=Surface area of hemishphere,cylinder and cone parts of tent
A=2πr
2
+2πrH+πr(
h
2
+r
2

​
)
A=2π×5×5+2π×5×13+π×5(
5
2
+12
2

​
)
A=770cm
2

Hope this helps u all. Thank you

Answer 2

Answer:

$\green{ \therefore Volume \: of \: toy = 1800\pi}$

Step-by-step explanation:

$\circ \: Radius = 20 \: cm \\ \\ \circ \: Height = 4.2 \: cm \\ \\ \bold{Using \: formula \: of \: cylinder} \\ \to Volume \: of \: cylinder = {\pi r}^{2} h \\ \\ \to Volume \: of \: cylinder =\pi \times {20}^{2} \times 4.2 \\ \\ \to Volume \: of \: cylinder =\pi \times 400 \times 4.2 \\ \\ \to Volume \: of \: cylinder = 1680 \pi - - - - - (1) \\ \\ \circ \: Height = 2.1 \:cm\\ \\ \bold{Using \: formula \: of \: cone} \\ \to Volume \: of \: cone = \frac{1}{3} \pi {r}^{2} h \\ \\ \to Volume \: of \: cone = \frac{1}{3} \times \pi \times {20}^{2} \times 2.1 \\ \\ \to Volume \: of \: cone = \pi \times 400 \times 0.3 \\ \\ \to Volume \: of \: cone =120\pi - - - - - (2) \\ \\ \text{Adding \: (1) \: and \: (2)} \\ \\ \to Volume \: of \: toy = 1680\pi + 120\pi \\ \\ \green{ \to Volume \: of \: toy =1800\pi }$