Question

please answer this question ​

Answer 1

Answer:

517

Step-by-step explanation:

radius= 7/2

height=20cm

total surface area = 2πr²+2πrh

total surface area= (2×22/7×7/2×7/2) + (2×22/7×7/2×20)

= 77+440= 517

Answer 2

The height h of cylinder = 20 cm

diameter of its base = 7 cm.

The radius r of its base = 3.5 cm.

Curved surface area of cylinder = 2πrh

= 2 × [22/7] ×3. 5 ×20

= 440 cm²

Now, curved surface area of one hemisphere = 2πr²

= 2 × [22/7] × (3. 5)²

= 77 cm².

Total surface area of the article = Curved surface area of cylinder + 2 [curved surface area of hemisphere]

= 440 +2(77)

= 440 +154

= 594 cm²

∴ Total surface area of the article when it is ready is 594 cm²