Check the three attached images.
The first exercise is quite self-explanatory. We have to draw two lines that pass through P and are tangent to the circle.
As for the second, since the circle is tangent to all three side of the triangle, we can conclude that the circle is inscribed in the triangle.
Finally, to draw the common tangent, you have to find the point of intersection between the two circles, and draw a line perpendicular to AB.
