How do you find the surface area of a cylinder??

Actually if the radius is r, the surface area is 4*pi*r^2

Would it be possible to find the surface area of a sphere?

if the radius is r, the surface area is 4*pi*r^2

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?

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.

How do you find the surface area of a cylinder

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) .

What if we don't have a decimal and just a normal number?

That's ok, you won't always get a decimal or fraction. Hope this helps, have a great day.

How do you find the height of a cuboid, when the length, the width and the surface area is given?

Surface area of cuboid = 2(lb+bh+hl) So you put the values and then solve.

how to find the area of a square pyramid?

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.)

Main content

6th grade

Course: 6th grade > Unit 10

Lesson 5: Surface area

Surface area review

Google Classroom

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.

[What is a net?]

Each of the sides is a 4 by 1, point, 5 rectangle.

\begin{aligned} \text{Area of a rectangle} &= \text{length} \cdot \text{width}\\\\ &= 4 \cdot 1.5\\\\ &= {6} \\\\ \end{aligned}

The total area of both sides is 2, dot, 6, equals, start color #11accd, 12, end color #11accd.

The bottom and the top are both 4 by 5 rectangles.

\begin{aligned} \text{Area of a rectangle} &= \text{length} \cdot \text{width}\\\\ &= 4 \cdot 5\\\\ &= {20} \\\\ \end{aligned}

The total area of bottom and the top is 2, dot, 20, equals, start color #1fab54, 40, end color #1fab54.

The back and the front are both 1, point, 5 by 5 rectangles.

\begin{aligned} \text{Area of a rectangle} &= \text{length} \cdot \text{width}\\\\ &= 1.5 \cdot 5\\\\ &= {7.5} \\\\ \end{aligned}

The total area of the back and the front is 2, dot, 7, point, 5, equals, start color #e07d10, 15, end color #e07d10.

Let's add the areas to find the surface area.

\begin{aligned} \text{Surface area} &= \blueD{12}+ \greenD{40} + \goldD{15} \\\\ &= 67\\\\ \end{aligned}

The surface area of the rectangular prism is 67 unitssquared.

Practice set

Problem 1

Current

Find the surface area of the square pyramid shown below.

unitssquared

Want to try some more surface area problems? Check out this exercise.

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Bee
Posted 6 years ago. Direct link to Bee's post “How do you find the surfa...”
How do you find the surface area of a cylinder??
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- TTV.StreamSniper.YT
  Posted 6 years ago. Direct link to TTV.StreamSniper.YT's post “Actually if the radius is...”
  Actually if the radius is r, the surface area is 4*pi*r^2
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David966★_
Posted 6 years ago. Direct link to David966★_'s post “Would it be possible to f...”
Would it be possible to find the surface area of a sphere?
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- Timber Lin
  Posted 6 years ago. Direct link to Timber Lin's post “if the radius is r, the s...”
  if the radius is r, the surface area is 4*pi*r^2
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Aeonos Shroud
Posted 6 years ago. Direct link to Aeonos Shroud's post “the question to find the ...”
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?
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(20 votes)
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- gopal2373
  Posted 5 years ago. Direct link to gopal2373's post “Basically, 2 1/2 equals 2...”
  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.
  Comment on gopal2373's post “Basically, 2 1/2 equals 2...”
  (19 votes)
Conner Steinborn
Posted 4 years ago. Direct link to Conner Steinborn's post “What if we don't have a d...”
What if we don't have a decimal and just a normal number?
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- P7 Logan, Aaron
  Posted 4 years ago. Direct link to P7 Logan, Aaron's post “That's ok, you won't alwa...”
  That's ok, you won't always get a decimal or fraction.
  
  Hope this helps, have a great day.
  Comment on P7 Logan, Aaron's post “That's ok, you won't alwa...”
  (15 votes)
Nicholes Adams
Posted 3 years ago. Direct link to Nicholes Adams's post “How do you find the surfa...”
How do you find the surface area of a cylinder
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- ®¥ħ@
  Posted a year ago. Direct link to ®¥ħ@'s post “The total surface area of...”
  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) .
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®¥ħ@
Posted 3 years ago. Direct link to ®¥ħ@'s post “How about to find the sur...”
How about to find the surface area of a hyperboloid?
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Vineetha V Banavar
Posted 5 years ago. Direct link to Vineetha V Banavar's post “How do you find the heigh...”
How do you find the height of a cuboid, when the length, the width and the surface area is given?
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(10 votes)
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- neelshaan2004
  Posted 4 years ago. Direct link to neelshaan2004's post “Surface area of cuboid = ...”
  Surface area of cuboid = 2(lb+bh+hl)
  So you put the values and then solve.
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  (9 votes)
Emily.Mitchell
Posted 4 years ago. Direct link to Emily.Mitchell's post “how to find the area of a...”
how to find the area of a square pyramid?
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(10 votes)
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- Ian Pulizzotto
  Posted 4 years ago. Direct link to Ian Pulizzotto's post “I assume you mean the sur...”
  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.)
  Comment on Ian Pulizzotto's post “I assume you mean the sur...”
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Jack Vazquez
Posted 3 years ago. Direct link to Jack Vazquez's post “I Get it but I still need...”
I Get it but I still need help and a little bit of practice
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aidenburgos
Posted 3 years ago. Direct link to aidenburgos's post “Why are questions called ...”
Why are questions called quetions... The more you know.........The less you are
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- Viccy
  Posted 5 months ago. Direct link to Viccy's post “why is this so funny to m...”
  why is this so funny to me? anybody else??
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