Surface Area Flashcards

All 6 cards in this deck

How do you find the total surface area of a prism?

e.g. a cuboid $7$ cm by $6$ cm by $5$ cm

Add the areas of all its faces.

$2(7\times6 + 7\times5 + 6\times5) = 214\text{ cm}^2$

What is the formula for the total surface area of a closed cylinder of radius $r$ and height $h$?

$2\pi r^2 + 2\pi r h$

The curved surface area alone is $2\pi r h$.

What is the formula for the surface area of a sphere of radius $r$?

$4\pi r^2$

What is the formula for the total surface area of a solid cone?

$\pi r l + \pi r^2$, where $l$ is the slant height.

True or false? The total surface area of a solid hemisphere of radius $r$ is $2\pi r^2$.

False. $2\pi r^2$ is only the curved part; the total is $2\pi r^2 + \pi r^2 = 3\pi r^2$.

What are the steps to find the surface area of a composite solid?

e.g. a cylinder of radius $r$, height $h$, with a hemisphere of radius $r$ on top

1. List the exposed surfaces of each part: curved cylinder, base circle, curved hemisphere.
2. Leave out any joined or hidden faces: the top circle of the cylinder.
3. Add the areas: $2\pi r h + \pi r^2 + 2\pi r^2$