Pythagorean: Find Side
About this exercise
Finding a shorter side when the hypotenuse is known.
Example problems
A few of the problems this exercise asks. The printable worksheet holds ten fresh ones.
- In a right triangle, the two legs are: a = 6, b = 8. Find the hypotenuse c.
- In a right triangle: leg a = 20, hypotenuse c = 29. Find the other leg b.
- In a right triangle: leg a = 9, hypotenuse c = 15. Find the other leg b.
- In a right triangle: leg a = 6, hypotenuse c = 10. Find the other leg b.
Try it yourself first — open a section below only if you get stuck.
How to solve it
Square the hypotenuse, subtract the square of the known side, then take the square root.
Worked example
With a hypotenuse of 13 and a side of 5, the other side is the root of 169 - 25 = 144, that is 12.
Common mistake
Adding the squares. When the hypotenuse is given, the missing side comes from a subtraction.