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Lesson 3: Volume with fractions

# Volume of a rectangular prism: fractional dimensions

The video explains how to calculate the volume of a rectangular prism with fractional dimensions. It emphasizes that volume equals the area of the base times the height. To find the volume, multiply the length, width, and height. The video also shows how to simplify fractions during multiplication. Created by Sal Khan.

## Want to join the conversation?

• He doesn't really thoroughly explain the part where he multiplies all of the fractions. I got confused and now i have no clue how to do it, could someone help me?
• What he means is 7 * 3 * 3/6 * 5 * 7.
It's equal to 7/7 * 3/6 * 3/5.
That's 1 * 1/2 * 3/5, which equals 3/10.
Do you understand now? If you need more help, ask me!
• i didn't know geometry was so hard!
• true! its really fun though when you get the hang of it
• How do you express the answer?
• Any unit to the third power because we are talking about 3D volume units. E.g. cm^3 or inches cubed.
• yes but cant just be yes because khan said so
• I'm not sure if this is right but I think the equation is
Length x width x height
Tell me if I'm right or wrong by commenting or a upvote/downvote.
• Yes, the volume of a rectangular prism is always length x width x height. Good job!
• What's the difference between V=bh and V=Bh?
• In geometric formulas, b usually refers to the length of the base of a 2-dimensional figure. B usually refers to the area of the base of a 3-dimensional figure. V=Bh is way should be written since V is measured in cubic units (u^3 = u * u * u), B is measured in square units (u^2 = u * u) and h is measured in linear units (u). I hope this helps.
• i do not under stand and i want to be able to ace most of my bench mark test
• It is basically the same as a regular rectangular prism. You multiply base and height (length x height x width).
• So basically we just multiply them all...