Similar triangles on SAT

Test Preparation SAT Preparation
1

<p>I have a problem with similar triangles, because oftentimes the triangles, from my perspective, only have equal angles, like this example below:
[Untitled-1.jpg</a> picture by BellyT_2007 - Photobucket](<a href=“Photo Storage”>Photo Storage)</p>

<p>In the official key, it says “Triangle ABD is similar to triangle BCE
, because they are right triangles with m<ABD= m<BCE .”</p>

<p>But do we need another equal angels, or at least two similar sides to declare those two triangles are similar?</p>

2

<p>ok look pretend you have a triangle XYZ and triangle ABC. Well angle x + angle y + angle z+ 180</p>

<p>and angle A + angle B + Angle C = 180</p>

<p>so if we say that Angle x is equal to angle A and angle Y is equal to angle b we get that angle Z = angle c b/c</p>

<p>X + Y + Z = A + B + C</p>

<p>X and A go away</p>

<p>Y + Z = B + C</p>

<p>Y and B go away</p>

<p>and we get Z = C</p>

<p>triangles can be proven similar using only 2 angles.</p>

3

<p>but there wasn’t another angles, besides the two right angles mentioned?</p>

4

<p>DancinggBear (correctly) assumes that Y=B and C=Z because of the fact that parallel lines cut by a transverse have equal corresponding angles: <a href=“http://www.geom.uiuc.edu/~dwiggins/pict16.GIF[/url]”>http://www.geom.uiuc.edu/~dwiggins/pict16.GIF&lt;/a&gt;&lt;/p&gt;

5

<p>line BD is parralel to CD because two lines perpendicular to the same line are parralel to that line. and since line AC is the transversal we can say that angle CBA is congruent (equal) to angle BAD because they are corresponding</p>

6

<p>yeah I get what yall saying
but what exactly is transversal line?</p>

7

<p>A line that cuts through 2 parallel lines. </p>

<p>EDIT: You may want to Google it for a more precise definition, though.</p>

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<p>Here: [jpeg.jpg</a> picture by VadimOsadchiy - Photobucket](<a href=“Photo and Video Storage | Photobucket”>Photo and Video Storage | Photobucket)</p>

<p>I hope this clears it up.</p>