Question

How do you find the missing length for the right triangle below the short side is 9cm and the hypotenuse is 30 cm?

Answer 1

28.62cm

Explanation:

The Pythagorean theorem is this: `a^2+b^2=c^2`, where `c` is the hypotenuse (which is the longest side and is opposite the right angle), and `a` and `b` are the other sides. Given the information we have, we can say that:
`9^2+b^2=30^2`, where `b` is the unknown side.
Now its a matter of rearranging and solving:
`b^2=30^2-9^2`
`b^2=900-81`
`b^2=819`
`b=sqrt(28.618)`
And if you type that into your calculator you'll get `b=28.62cm` (Don't forget units)