Question

A toy is in the form of a 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 the toy.​

Answer 1

Answer:

214.5cm^2

Step-by-step explanation:

total surface area of toy=curved surface area of cone+surface area of hemisphere

curved surface area of cone=πrl

r=3.5cm

height=15.5-3.5=12cm

I=12.5cm

l^2=h^2+b^2

therefore CSA of cone=π×3.5×12.5

=137.5cm^2

surface area of hemisphere=2πr^2

=2×π×[3.5]^2

=77cm^2

hence,TSA of toy=77+137.5

=214.5cm^2

hope it is helpful.

Answer 2

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Given that the radius of the cone and the hemisphere (r) = 3.5 cm or 7/2 cm

The total height of the toy is given as 15.5 cm.

So, the height of the cone (h) = 15.5-3.5 = 12 cm

∴ The curved surface area of cone = πrl

(22/7)×(7/2)×(25/2) = 275/2 cm2

Also, the curved surface area of the hemisphere = 2πr2

2×(22/7)×(7/2)2

= 77 cm2

Now, the Total surface area of the toy = CSA of cone + CSA of hemisphere

= (275/2)+77 cm2

= (275+154)/2 cm2

= 429/2 cm2 = 214.5cm2

So, the total surface area (TSA) of the toy is 214.5cm2