Question

the total surface area of a hollow cylinder whose external and internal radii are 4 cm and 3 cm

respectively and height is 14 cm.​

Answer 1

Answer:

660cm2

Step-by-step explanation:

Given internal radius r=3 cm

External radius R=(3+1) cm (Since thickness is 1 cm)

∴ Total surface area =2π(R+r)(h+R−r)

==2×  

7

22

​  

×(4+3)(14+4−3)=  

7

44

​  

×7×15=660cm  

2