A tree is broken at a height of 5 m from the ground and its top touches the ground at a distance of 12 m from the base of the tree. Find the original height of the tree.
Let ABC is the triangle and B is the point where tree is broken at the height 5 m from the ground.
Tree top touches the ground at a distance of AC = 12 m from the base of the tree,

By observing the figure we came to conclude that right angle triangle is formed at A.
From the rule of Pythagoras theorem,
BC2 = AB2 + AC2
BC2 = 52 + 122
BC2 = 25 + 144
BC2 = 169
BC = √169
BC = 13 m
Then, the original height of the tree = AB + BC
= 5 + 13 = 18 m