Question

A ladder is placed against wall such that it s foot is at a distance3.5 m from the wall and it's top reaches a window 12m above the ground find length of the ladder

Answer 1

here it forms a triangle

length of the ladder will be the hypotenuse

${hyp}^{2} = {adj}^{2} + {opp}^{2} \\ {hyp}^{2} = {(3.5)}^{2} + {12}^{2} \\ = 12.25 + 144 \\ = 156.25 \\ hyp = \sqrt{156.25} \\ = 12.5m \\ length \: of \: ladder \: = 12.5m$