Srivani walks 12 m due East and turns left and walks another 5m , how far is she from the place she started?

A man goes 40 m due East and then 80 m due North. Find his distance form the starting point.

A man goes 40m due East and then 96m due North. Find the distance from the starting point.

A 30 kg boy stands at the far edge of a floating plank, whose near edge is against the shore of a river. The plank is 10 m long and weighs 10 kg. If the boy walks to the neat edge of the plank, how far from the shore does the plank move