Question

plz urgent
i will thank your all answers​

Answer 1

Answer:

3168cm^2

Step-by-step explanation:

Solution :

Length of the pipe, h = 20 cm

External radius of the pipe, R=252cm=12.5cm

Thickness of the pipe = 1cm

Internal radius of the pipe, r=(12.5−1)cm=11.5cm

Total surface area of the pipe

= (external curved surface area) +

(internal curved surface area) + 2(area of the base ring)

=[2πRh+2πrh+2(πR2−πr2)] sq units

[2πh(R+r)+2π(R2−r2)] sq units

=2π(R+r)[h+(R−r)] sq units

=2×227×(12.5+11.5)(20+12.5−11.5)cm2

=(2×227×24×21)cm2=3168cm2