SOLUTION: A rectangle is twice as long as it is wide. If the width is a, what is the length of its diagonal??

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Question 945792: A rectangle is twice as long as it is wide. If the width is a, what is the length of its diagonal??
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
The sides of the rectangle are the legs of a right triangle with the diagonal as the hypotenuse.
Use the Pythagorean theorem,
a%5E2%2B%282a%29%5E2=D%5E2
a%5E2%2B4a%5E2=D%5E2
D%5E2=5a%5E2
D=sqrt%285%29a