Hello! This question is really easy, here it is!
Answer: Picture A, and picture B.. But how did I find that out?
Step-by-step & Explanation: Okay, when you're trying to figure out what triangle or shape in general is congruent. You need to know what congruent means first. Congruent means equal. (So keep that in mind) Now, you need to know how to figure out how I got this.
First, look at picture A. Both shapes are around the same size, except one of them are flipped to the side. So, if you flip that back to the correct side, you can see that they are exactly equal. Such as, the line of D and E. There is one line in between them. Then, look at the other triangle. Woah! There is a side that looks almost identical! But, what's in-between it?! One Line! If you continue this, between all lines of both triangles. They all show they have equal in-between lines.
Now, that was a mouth full. But! You still need to know how I got Picture B! So, let's continue.
As you can tell, that triangle has numbers beside it. (Same with the other one.) BUT NOT TO WORRY! NO DIVIDING IS IN THIS PROBLEM! Because... These numbers represent BLOCKS. So, now. Look at the line from T to V. What's that number in-between? A 7! So, that side is 7 blocks. Now look, all sides have numbers beside it! Let's take a look at the line W and Y. Wait! What's that number in-between?! Another 7! If you look all around those sides, there are numbers. That are exactly identical to the other triangle. Which! MAKES THEM CONGRUENT. Or, equal!
Lastly. How are the others not equal? Well, we've really figured out the whole "congruent" stuff. So, it really makes since that the others are clearly not it. For example: Picture C. All of the sides don't match up to the other triangle. Example: Picture D. The sides aren't congruent to the other triangle as well.
This was a bunch to read, but if you've finished it. Hopefully it makes more since to understand this problem. Thanks!