ACT Math : How to find the length of the diagonal of a rectangle
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Example Questions
Example Question #2 : How To Find The Length Of The Diagonal Of A Rectangle
A rectangle has a height of 
1. Use Pythagorean Theorem with 
2. Solve for 
This rounds down to 
Example Question #1 : How To Find The Length Of The Diagonal Of A Rectangle
The sides of rectangle ABCD are 4 in and 13 in.
How long is the diagonal of rectangle ABCD?
A diagonal of a rectangle cuts the rectangle into 2 right triangles with sides equal to the sides of the rectangle and with a hypotenuse that is the diagonal. All you need to do is use the pythagorean theorem:
Example Question #123 : Quadrilaterals
A power company needs to run a piece of wire across a rectangular plot of land and must do so diagonally. The land is 
Notice that this problem could be represented as follows:
This means that you can find the distance of the wire merely by using the Pythagorean theorem:
Solving for 
Thus,
Using your calculator, multiply this by 
Example Question #1 : How To Find The Length Of The Diagonal Of A Rectangle
What is the diagonal of a rectangle with sides of length 
You could draw this rectangle as follows:
Solving for the diagonal merely requires using the Pythagorean theorem. Thus, you know:
This is approximately 
Example Question #125 : Quadrilaterals
What is the area of a rectangle with a diagonal of 
Based on the description offered in the question, you know that your rectangle must look something like this:
Using the Pythagorean theorem, you can solve for the unknown side 
Thus, 
Example Question #126 : Quadrilaterals
Mark bought a TV at the store that was listed as 36in x 24in. He needs to figure out the diagonal to make sure the television is large enough but he left his measuring tape at his mother's house. What is the diagonal length of this television's screen in terms of inches?
Finding the diagonal of a rectangle is essentially a problem with triangles. If we set up a right triangle with legs 24 in. and 36 in., and set 
This comes out to be about 43.3 in.
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