 Here I have two triangles. They kind of share a side and I need to identify the congruent triangles by their names So I've got a triangle on top a triangle on bottom It doesn't matter which one I start with but I'll just start with the top one for fun so I've got let's say triangle ABC and To start off it doesn't really matter what you name the very first one I just happen to go in alphabetical order now triangle ABC is congruent to which triangle The order of the letters that you pick is very important here I started with ABC start at a head toward B and up at C I'm gonna follow the same steps to name the second triangle in other words I'm going to follow along this segment that has one congruence mark and then I'm gonna follow down this other segment with two congruence marks. So start at a head towards C So for the second triangle, I'm gonna follow the same method just Down the other direction start at a head toward D and up at C So that triangle is named a D C Here's another example We can start with the triangle on the left or the triangle on the right doesn't really matter which one you start with I think I'll start with the one on the left. Let's say triangle PQS and which one is that congruent to? so we start at P and Angle P that angle is made up of a Segment with two congruence marks and a segment with one congruence mark So that tells me angle P is corresponding with angle R So I know that the second triangle's name will start with R Now I go from P to Q which follows along this segment with one tick mark So that means I'll have to follow from R along the same segment. So PQS and R QS Take a minute and try this next example on your own. Here's one possibility M and O is congruent to QPO There are other possibilities as well That's another possibility Can you think of another possibility? Let's take a look at another example Lastly, so we've got this triangle down below here. Let me just shift up a little bit We're dealing with triangle RTV, let's say So what are we going to name our second triangle if we start at R? That angle is made up of a congruence segment two and three And so I need to start at angle U The reason is it's also made up of a segment with two and three congruence marks So R corresponds with U Now we moved from R to T to V So R Towards T Head up at V Again, we're gonna start at U We're gonna move along that parallel line and end up at V So it should be U Sv and those are those congruent triangles