Question

o find
CSA , TSA and Volume of toy which base is hemisphere, radius is 7 cm middle is Cylinder with radius 5cm and top is conical which radius is 3cm, if height of cone and cylinder 10cm​

Answer 1

Step-by-step explanation:

Total surface area (T.S.A) = 616 cm2.

Let r be the radius of cylinder and h be the radius of cylinder.

As per given statement:

(curved surface area / (total surface area) = 1 / 2

or CSA = 1 /2TSA

CSA = 1 /2 x 616 = 308

⇒ CSA = 308 cm2

Now,

TSA = 2πrh + 2πr2

⇒ 616 = CSA + 2πr2

⇒ 616 = 308 + 2πr2

⇒ 2πr2 = 616 – 308

⇒ 2πr2 = 308

⇒ r2 = 308/2π

⇒ r2 = 49 or r = 7 cm …(1)

As,

CSA = 308 cm2 2πrh = 308

⇒ 2 x 22 /7 x 7 x h = 308 (using (1))

⇒ h = 7 cm

Now, Volume of cylinder = πr2h = 22/7 x 7 x 7 x 7 = 1078

Therefore, Volume of cylinder is 1078 cm2.