# Vector VS Plane intersection

Could You help me with task:

From point $M(3,5)$ that belongs to plane: $A(0,0), B(0,10), C(20,10), D(20,0)$, comes out vector $V$ at an angle a(with $OX$).

Need to find point $X(x,y)$ at which he will be leaving the plane.

Thanks.

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Observe that $y=10$ and $\tan\alpha=\frac{10-5}{x-3}$.