## anonymous 4 years ago surface area of a cylinder?

1. anonymous

Surface Area = 2(pi r 2) + (2 pi r)* h

2. anonymous

a tin soup is in the shape of a cylinder. it has a radius of 3cm and its height is 12cm. the tin has a label which fits exactly around the cylinder with no overlap. calculate the area of the label with 3 significant figures.

3. jiteshmeghwal9

$$\Large{2 \pi rh+2\pi r^2}$$

4. anonymous

2(pi 3^2)+(2pi 3)x12

5. anonymous

what does the arrow mean that goes upwards?

6. anonymous

Cylinder: Two circles and the curved surfaces Area of Circle: pi*r^2 Area of curved surface: circumference of ^ circle * height of cylinder circumference: 2*pi*r so area of curved surface: 2*pi*r*h Total area: 2*pi*r^2 + 2*pi*r*h =2*pi*r(r+h)

7. anonymous

The ^ means to the power of e.g. 5^2 = 25

8. anonymous

oh thanks!

9. anonymous

In your question, the label is the area of the 'curved surface'. Which we showed to be 2*pi*r*h

10. anonymous

thank you @apple_pi

11. anonymous

sure, anytime