 In order to find the area of arombus, remember that you need the diagonals, and the diagonals are perpendicular. So, the area of arombus is one-half times one of the diagonals. Let's call it D1 times the other diagonal, D2. And there are some links on Moodle to help you understand why that is the case. So let's try a couple of example problems. So we see that this is arombus. It says so in the directions. And so to find the area, we'll use the area formula, one-half D1 times D2. So one of the diagonals I see is 20 plus 20. In other words, it's 40. And the other diagonal is 10 plus 10. In other words, it's 20. So area is one-half times 40 times 20. Now, your note sheet might be slightly different than that example. And so if you have different diagonals, make sure that you substitute in the proper values. I think your note sheet says instead of 20, it says 12. So be careful. And with this next example, we want to find the area of this arombus. However, we're missing some lengths of diagonals. We do know that the diagonals are perpendicular. And in particular, in this triangle, well actually in all of these triangles, we have a 30, 60, 90 triangle. 12 refers to the hypotenuse of the 30, 60, 90. Let me just recreate that down here. So we know that the hypotenuse is 12, and that means the short leg is 6 and the long leg is 6 root 3. And so this length is 6, which makes this length also 6. And then in the longer diagonal, this length is 6 root 3 and 6 root 3. And so the area, area formula for arombus is one-half d1 times d2. And so the area in this case, one-half times the red length. So this red length we knew was 6 and 6, which together makes 12. And then times the blue length, and we have 6 root 3 plus 6 root 3, which makes 12 square roots of 3. And now all that's left to do is start multiplying. Area is one-half times 12 is 6, and 6 times 12 is 72. So we have 72 square roots of 3 square units. 72 root 3. There we go.