Question

A right circular cylinder has a base whose area is 154 square feet. If the height of the cylinder is 19 feet, what is its lateral surface area? Use π = 22/7

Answer 1

836 ft^2
990 ft^2
1672 ft^2
1980 ft^2

Answer 2

Can you also help me with this one please?

Hena stores coffee powder in a steel container with a capacity of 82.5 cubic inches. He uses a glass container to store sugar. The two containers are congruent cylinders. If the glass container has a height of 4.2 inches, what is its radius?

2.5 inches
4.2 inches
4.4 inches
8.4 inches

Answer 3

We know that the area of a circle is given by pi * radius squared, so we can work out the radius of the cylinder as \[\sqrt{area/\pi}\].
We can then work out the circumference of the circle as this is given by\[ 2\pi r\]. We can substitute our expression for the radius into this to give:\[Circumference = 2\pi \sqrt{area/\pi}\] which simpifies to:\[2\sqrt{154\pi}\]Substituting our value for the area and for pi we get \[2\times\sqrt{154\times22/7} \]
Since 154 is 22 * 7 we get 22 for the root and a total circumference of 44. The lateral area is then this times the height of the cylinder (imagine the cylinder unrolled into a rectangle) which gives 44 * 19 or 836.