Question

A triangle has sides A, B, and C. Sides A and B are of lengths `7` and `9`, respectively, and the angle between A and B is `(pi)/2`. What is the length of side C?

Answer 1

`color(white)(xxx)sqrt130`

Explanation:

`color(white)(xx)M(/_C)=pi/2<=>C^2=A^2+B^2color(white)(xxxxx)`Pythagoras' Theorem

`=>C^2=color(red)7^2+color(red)9^2`
`=>C=sqrt(49+81)`
`color(white)(xxx)=sqrt130`