I’M going to look at another example here for similar triangles, so just take a second here. We’Ve got a couple of triangles. We have a couple of parallel lines, so we want to do in this question. Is we want to firstly notice that three plus six should be nine, so the whole length of that top side is going to be nine, because we know that we can actually take that small triangle and move it down here.

So we now have some similar sites. Three and nine are going to be similar and four, and the bottom will call that bottom bc, so we can set up our propulsion. We’Ve got three over for those poll. Numbers are both in the same triangle set equal to 9 over BC.

Bc is going to be this bottom side right here. So what we’ll do next is a little cross. Multiplying we’re going to go three times bc, we’re going to set that equal to nine times. Four and one extra step included here was they’ll divide.

Both sides by 3, meaning bc, should work out to be 12