Question

There is a ladder resting against a wall of height 8m with a top of ladder coinciding with the of wall. when the foot of ladder is moved 2m away from the wall; the top of ladder slips down & coincides with the foot of the wall .find the length of ladders

Answer 1

let the length of ladder be x
then distance between their foots= x-2
then by pythagoras theorem
(x-2)(x-2) + 8*8 = x*x
x*x + 4 -4x + 64 = x*x
68 = 4x
x = 17m