Three vector ` vec A, vec B` and vec C` are such that ` vec A= vec B+ vec C` and their magnitude are ` 54,3, respectively. Find the angle between ` vec A ` and vec C`.

Explanation

Since , ` 5^2 = 4^2 + 3^2 `, therefore ` A^2 +B^2 + C^2`. It means angle between ` vec B` and ` vec C` is ` 90^@`. If ` theta` is the angle between ` vec A` and ` vec C`, then
`cos therta = 3//5 = 0.6 = cos 53^2 8'` or ` theta = 53^@ 8'`.