find the total surface area of aa cylinder of height 20 cm and curved surface area 1760 cm2 please answer me
Answers
Answer:
1785.14 sq.cm
Step-by-step explanation:
Curved surface area= 2* pi * r* h,
where,
r= radius of cylinder and h= height of cylinder
Just for understanding: ( Just think like circles of radius r are being stacked on top of one another upto a height h and that figure gives us nothing but a cylinder of radius r and height h. That's why we say cylinders have circular cross section. so, Curved surface are is nothing but the product of circumference of circle ( 2*pi*r) and height (h) and thats how we get 2* pi* r*h)
The above note is not a part of the sum and just for understanding.
So,
Curved surface area= 1760
=> 2* pi* r* h = 1760
=> 2* (22/7)* r* 20= 1760
=> r= 2 cm
So, Total surface area = Curved surface area + Area of circle on top+ Area of circle in bottom
Since radius of circles on top nd bottom are equal,
Total surface area = Curved surface area + 2* Area of circle on top/bottom
= 1760+ 2* (22/7)* 2*2 [ r= 2cm and area of circle = pi*r*r]
= 1760 + 176/7
= 1785.14 sq.cm