If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Solving a scale drawing word problem

See how we solve a word problem by using a scale drawing and finding the scale factor. Created by Sal Khan.

Want to join the conversation?

• at , he says the dimensions is 40x40, presuming it's a square, but it says rectangular up above. I know a square is a rectangle, but how could he be sure those were the dimensions?
• He could do the reverse operation to check his work
• is it just me im having a very hard time with these types of probs
• He never says what would happen if you were trying to do an odd number!
It woud be a little bit ore complacated but he should at least talk about it.
• Sal uses too much vocab! What are dimensions! SAL IS TOO SMART! IM NOT!
• Dimension is the length,width,height,or depth of something.
• If an object 1'-6" long drawn at a scale of 1 1/2" = 1'-0", how long is the drawing?
• If you dont understand what he is saying so basically he is trying to tell you how to get the area by multiplying with inches or anything to get the answer of the area for something a bit simple and better for you for those people who dont understand here is an example My area is 1800 to get it its 90 times 90 I got this by 9*9=18 and 90*90=1800 so he is trying to show you what he is doing and explaining the steps to do this type of method.
• Is there any way to do this without doing all the scratchpad work?
• It is all right to work with a pencil and paper but if you have the brain power, it is quite easy to do it in your brain. just find out the square root as shown in the video and work from there. It is always perfectly fine to use a pencil and paper and it is necesary alot of the time but on easier problems all you would need to do is jot down a few numbers!
• How do I determine the scale factors for the three rectangles
• You need to figure our how much each area is multiplied and that would be the scale factor, I think. Hope this helps!
(1 vote)
• why you multiply directly 3 inches * 40
• Hey Harshil! So the information we have been given is that the real dining room is 1600 times larger in area. That means one side or one length of the dining room is 40 times larger (as explained by Sal).

I think the key word here is: "larger than". If the drawing is 3 inches, the real things is 40 times larger than that. So if we want to know how long the real dining room is, we can multiply these two numbers with each other.

Does that help?