1 25Below is a half cylinder joined to acuboid. What is its surface ar

1.	1 25Below is a half cylinder joined to acuboid. What is its surface area?(Take a = 22).5 cm20 cm7 cmB.707.5 cm598.5 cm668.5 cm?630 cm2
Answer» Surface area of cuboid= 2(lh + bh) + lb= 2(205 + 75) + 140= 2(100 + 35) + 140= 2135 + 140= 270 + 140 = 410 cm^2 Curved surface area of half cylinder = pirh= 22/77/220= 11*20= 220 cm^2 Total surface area= 410 + 220= 630 cm^2 (D) is correct option

1 25Below is a half cylinder joined to acuboid. What is its surface area?(Take a = 22).5 cm20 cm7 cmB.707.5 cm598.5 cm668.5 cm?630 cm2

Answer»

Surface area of cuboid= 2(l*h + b*h) + l*b= 2(20*5 + 7*5) + 140= 2(100 + 35) + 140= 2*135 + 140= 270 + 140 = 410 cm^2

Curved surface area of half cylinder = pi*r*h= 22/7*7/2*20= 11*20= 220 cm^2

Total surface area= 410 + 220= 630 cm^2

(D) is correct option