Question

For the following figure, establish that the triangles are similar, and hence find x (see comments) PLEASE HELP !!! I HAVE A TEST -.-

Answer 1

If the triangles are similar, they are only increased or decreased by a factor in relation to one another. So 12/10=x/9. Because the sides are only multiplied by a factor in order to increase the size without effect on the angles, so the relationship between the sides must be the same.

Answer 2

Since lines BE and CD are parallel, corresponding angles are congruent.
That means angle ABE is congruent to angle C
and angle AEB is congruent to angle D
Angle A is congruent to itself.
By AAA, the two tirangles are similar

Answer 3

Once you established the triangles are similar, use a proportion to find x

Answer 4

Thanks guys but I already knew that part, but I don´t know how to find the x without having any information about the parallel lines -.-

Answer 5

You cant, I was assuming those signs on the lines meant that they were paralel, because otherwise you cant solve it

Answer 6

Yeah they are parallel but I don´t know how long they are but I just realized that it doesn't matter anyways.. I tried solving it like this \[\frac{ AE }{ AD } = \frac{ AB }{ AC }\] but it´s not working

Answer 7

It should work...

Answer 8

It should work. Your proportion is correct.

Answer 9

Make sure you use the correct values for AD and AC. AD = AE + ED, and AC = AB + BC = x + 9

Answer 10

Oh thanks I think I did something wrong when I tried solving it the first time... Thanks again :D