In circle k(O), AC is a diameter, AB is a chord, and MA is tangent to the circle. Angle ∠MAB is acute. Prove that m∠MAB=m∠ACB.

Awoman has 14 different shirts: 10 white shirts and 4 red shirts. if she randomly chooses 2 shirts to take with her on vacation, then what is the probability that she will choose two white shirts? show your answer in fraction and percent, round to the nearest whole percent.