Question

in a triangle PQR, right angled at Q, PQ=24 and QR=7. S is the mid point of PR. then RS is?

Answer 1

since pqr is a right angled triangle, pr is the hypotenuse, pq is the altitude and qr is the base.
so hypotenuse will be equal to the root of base square plus altitude square[pythagorus theorem] 
so hypotenuse[pr]= root of 24 square + 7 square
                            = root of 576+49
                            = root of 625
                            = 25
now S is the midpoint of PR[given]
which means ps=rs
therefore half of pr= half of 25=RS
hence,RS=25 divided by 2
               =12.5