Answer:
The two triangles in 8 are not similar. The two triangles in 9 are similar.
Explanation:
The three angles of all triangles must add up to 180°.
The left triangle in 8 has these angles:
46 58 and (180 - (46+58)) = 76
The right triangle in 8 has these angles:
58 78 and (180 - (58+78)) = 44
So, 46 | 44 and 76 | 78 are dissimilar.
The left triangle in 9 has these angles:
106 31 and (180 - (106+31)) = 43
The right triangle in 9 has these angles:
31 43 and (180 - (31+43)) = 106
But the triangles in 9 all have the same angles: 31 | 43 | 106.