Answer:
No, the first pair of triangles are not similar.
Explanation:
Similarity is when you divide or multiple a certain shape to a certain size, so that it will fit in exactly with the other shape it is compared to.
For this triangle, this is impossible to achieve.
The reason you can tell this is because off the bat, we see that the sides are not similar, and have a different ratio from each other (16 equals 16, while 39 does not equal 40)
Thus, these two pairs of triangles are NOT similar to each other.