SIMILAR TRIANGLES!!!

[astone788]

Need help with this question: VCAA further 1 2011
To makes things clear I have oriented the triangles so that they align. By doing this we can see that the corresponding sides do not match up. So how on Earth are these two triangles similar?

[StumbleBum]

No, you aligned the triangles wrong. You must flip it so the angle is in the same position and so that it remains connected to the point A in the same way that the bigger triangle is, if that makes sense?

So in turn the side 24, would actually be on the bottom. Then using the scale factor you will get    which you then need to square as we are working with area, so    then you times this by the original 100cm^2 and you get 278cm^2, the answer.

[Daenerys Targaryen]

the smaller triangle make the A at the top and D at the left bottom and B leave it

[TheRajinator]

They do match just check where the hypotenous is. the orientation of your triangle is incorrect. The AB side should be on the top.

[astone788]

really hard to flip the triangles by imigination. Can we bring in scissors and paper to cut out triangles, to remove the guess work. Especially when your in a hurry, theres bound to be human error. Cutting out triangles would remove human error. Can't beleive no one has brang this up.

EDIT: I tried rotating it, but I still cant seem to orient it properly. The only way to do it properly is to flip the triangle like a pancake. But in my experience, whenever I do this, it doesn't work out. wtf?

[StumbleBum]

really hard to flip the triangles by imigination. Can we bring in scissors and paper to cut out triangles, to remove the guess work. Especially when your in a hurry, theres bound to be human error. Cutting out triangles would remove human error. Can't beleive no one has brang this up.

You could remove the human error by realising that the only two common points (A and B) must be in the same position (along with the angle) for them to be similar. Drawing out the altered triangle was a good idea, you just dint pick up on your mistake of putting A on the bottom.

[astone788]

the only two common points (A and B) must be in the same position (along with the angle) for them to be similar.

can you illustrate this plz.

[StumbleBum]

the only two common points (A and B) must be in the same position (along with the angle) for them to be similar.

can you illustrate this plz.

Sorry i men't that the only common point is A and the angle, therefore they must both be in the same position on each triangle for them to be similar. That should make more sense?

[Conic]

Here's my working:

[astone788]

still dont see how these triangles are similar. I rotate and orient the triangles, however the sides and angles do not correspond.

[Conic]

VCAAs diagrams are not necessarily scaled accurately. Check my working.

[astone788]

I dont know man. Harderest question I've ever seen in my life.

[astone788]

VCAAs diagrams are not necessarily scaled accurately.

Looking at my textbook I've never seen a question like this. I guess it's best not to think too much and go with the flow regardless that it doesnt hold true to the law of similar triangles.

[Conic]

But they are similar? It does hold up.

[astone788]

How?? When you orient the figures together, there are no two corresponding sides e.g.

we need two corresponding lengths to establish the scale factor between two similar triangles.