Physics question, please explain how?

Question

You're rowing a boat perpindicular to the shore of a river that is flowing at 3 m/s. The velocity of you're boat is 4 m/s relative to the water. What is the velocity of your boat relative to the shore? and what is the component of your velocity parallel to the shore?

Answer 1

Parallel is the speed of the river: 3 m/s

the v relative to shore is
sqrt(9+16)
or 5 m/s
at and angle of
ATAN(3/4)

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