Two circles touch each other externally at P. AB is a direct common tangent to the two circles, A and B are points of contact, and ∠PAB = 40°. The measure of ∠ABP is:

50°

According to the concept, \(\angle\)APB = \({90}^\circ\)

Considering \(\Delta \)APB

\(\angle\)APB

⇒ \({90}^\circ\) - \(\angle\)PAB

⇒ \({90}^\circ\) - \({40}^\circ\) = \({50}^\circ\)

Therefore, \(\angle\)APB is \({50}^\circ\)