The image of the triangle and the corresponding lines is needed in order to answer this question properly. That image is attached.
We are told that point P is the incenter of the triangle, and is the center point of the incircle of the triangle. The incircle is the largest circle that can be made in a triangle and is tangent to each side of the triangle. The radius of the circle is going to be a perpendicular line from point P to any side of the triangle. In the triangle shown, PZ = PY = PX, and each value is equal to the radius of the circle.
Therefore, no further calculations are required for this problem since we already know that PZ = 7 units making the radius, r = 7 units.