 This video is called Practice Problems 1. The practice problems videos that you are about to watch are designed to help you with your book work and to prepare for your quizzes and your tests. Basically, if you took quality notes and paid attention onto the videos you've already watched today, you should be able to answer these next, you should be able to do the problems on these next videos without too much trouble. We're just trying to get you used to the style of questions that will be asked and some things you might see in your book assignment or on a test. So this first question that asks which sets of segment lengths will not create a triangle, you will see this on your book work and you will see this on quizzes and tests. So make sure you take good notes and you know how to solve a problem like this. So we've learned already in previous videos that to create a triangle, the two smallest segments have to add up to be bigger than the largest one. So for A, when the side lengths or the segment lengths are 2, 3, and 1, you're going to pick the smaller two and add them together. 2 plus 1 gives you 3. Now in order for this to make a triangle, I need my answer, my sum, to be bigger than the third side. Well the third side is 3 so they equal to each other. It's not bigger so this one will not create a triangle. Let's look at B. We have side lengths of 2, 3, and 2. Can these create a triangle? Pick the smallest two and add them up. 2 plus 2 equals 4. And now we're going to compare it with the biggest side of my triangle which is 3. Well 4 is bigger than 3 so the sum of my two smaller sides is bigger than my largest side. So I can say yes, I have a triangle. Let's look at the third example, example C. I've got side lengths or segments of 2, 3, and 4. Can this make a triangle? Pick the smaller two and add them up. 2 plus 3 is 5. Now I'm going to compare it with the biggest segment that I was given. Since 5 is bigger than 4, the sum of the two smaller ones is greater than the longest segment. I can say yes, I have a triangle. So then lastly the last example is D. I have segment lengths of 2, 3, and 5. I add up the two smaller ones. 2 plus 3 is 5. I need to compare that with my longest side and in this case they're equal. So I do not have a triangle. So this problem says which sets of segment lengths will not create a triangle. My answer would be A and D because A and D do not create a triangle.