#1**+1 **

angle(PAB) is a right angle because it is formed by a diameter and a tangent

angle(ACB) is a right angle because it intercepts a semicircle.

angle(PCA) is a right anlge because it forms a straight line with angle(ACB).

Therefore, angle(PAB) is congruent to angle(PCA).

angle(P) is congruent to angle(P) by identity.

Therefore, the two triangles are similar by AA.

geno3141 Apr 27, 2020