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Course: Grade 8 (VA SOL) > Unit 7
Lesson 3: Surface area- Surface area using a net: triangular prism
- Surface area using a net: rectangular prism
- Surface area of a box (cuboid)
- Surface area of a box using nets
- Surface area using nets
- Expressions to find surface area
- Surface area
- Surface area versus volume
- Surface area word problem example
- Surface area word problems
- Surface area review
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Surface area review
Review surface area and try some practice problems.
What is surface area?
Surface area is the amount of space covering the outside of a three-dimensional shape.
Finding surface area
To calculate surface area, we add the areas of all the faces of the three-dimensional figure.
Want to learn more about finding surface area? Check out this video.
Example: Rectangular prism
Find the surface area of the right rectangular prism shown below.
Let's draw a net of the rectangular prism.
Each of the sides is a by rectangle.
The total area of both sides is .
The bottom and the top are both by rectangles.
The total area of bottom and the top is .
The back and the front are both by rectangles.
The total area of the back and the front is .
Let's add the areas to find the surface area.
The surface area of the rectangular prism is units .
Want to join the conversation?
- How do you find the surface area of a cylinder??(113 votes)
- Actually if the radius is r, the surface area is 4*pi*r^2(63 votes)
- Would it be possible to find the surface area of a sphere?(41 votes)
- if the radius is r, the surface area is 4*pi*r^2(25 votes)
- the question to find the surface area of a square with sides 2 1/2 confuses me. can someone please explain in detail how to solve this problem?(21 votes)
- Basically, 2 1/2 equals 2.5. So the easiest way to do that is obviously by multiplying 2.5*2.5*6 By the way, * equals multiply.(22 votes)
- What if we don't have a decimal and just a normal number?(12 votes)
- That's ok, you won't always get a decimal or fraction.
Hope this helps, have a great day.(24 votes)
- How do you find the surface area of a cylinder(15 votes)
- The total surface area of the cylinder formula is the sum of the base surface area and the lateral surface area: total_area = base_area + lateral_area , or total_area = 2 * π * r² + (2 * π * r) * h , or total_area = 2 * π * r * (r + h) .(10 votes)
- how to find the area of a square pyramid?(10 votes)
- I assume you mean the surface area, since a square pyramid is 3-dimensional.
For a right square pyramid with base side length s and slant height L, the total surface area is the area of the square base with side length s, plus the total area of four triangles each with base s and altitude L. So the total surface area is
s^2 + 4(1/2)(sL) = s^2 + 2sL.
(Note well: the slant height is not the same as the vertical height.)(14 votes)
- I Get it but I still need help and a little bit of practice(17 votes)
- i don't get it either(0 votes)
- Why are questions called quetions... The more you know.........The less you are(14 votes)
- why is this so funny to me? anybody else??(3 votes)
- How do you find the height of a cuboid, when the length, the width and the surface area is given?(11 votes)
- Surface area of cuboid = 2(lb+bh+hl)
So you put the values and then solve.(9 votes)
- How about to find the surface area of a hyperboloid?(13 votes)