28. In the larger triangle, angle R=180-78-63=180-141=39, which is equal to angle V in the smaller triangle. Also, <P=<W, , <Q=<U, therefore the two triangles are similar.

29. <G=180-110-33=180-143=37, which is not equal to <C, so these two are not similar.

30. <1+<2=90, <2+<3=90, <3+<4=90, so <1=<3, <2= <4, so the two triangles are similar.

31. PM and KL are parallel, so <NMP=<NLK; similarly, NP AND KJ are parallel, so <MNP=<MJK. So the two triangles are similar.