<p>does anybody remember how to do this?</p>
<p>i kno you can get area with just sides using Hero's formula..</p>
<p>but how do you get angle measures when you just know the sides?</p>
<p>bump…</p>
<p>Do you mean heron’s formula? You don’t need to know any of that for the psat or sat.</p>
<p>yeah Heron’s formula for area of the triangle and to find angles you could use a variation of the Law of Cosines: arccos(((c^2)-(a^2)-(b^2))/(2ab))= angle C and so on and so forth</p>
<p>Law of cosines
a^2 = b^2 + c^2 - 2bc cos A</p>
<p>To find the area
A = 1/2 ab sin C</p>
<p>again, far beyond the scope of SAT or ACT.</p>
<p>perhaps appropriate for Math II, but even so i think not</p>
<p>Uhhh, idk what Heron’s formula is. x_x</p>
<p>But to answer your question, I believe that simple trigonometry (sin, cos, tan) would work. Remember SOHCAHTOA?</p>
<p>Yeah, no point throwing around the cosine rule and all. I presume they’ll only ask about right angled triangles in the SAT I…</p>
<p>Just use SOHCAHTOA, from 8th grade trig.</p>
<p>If it’s not right angled, then yeah, go ahead and use the cosine rule…</p>
<p>if all else fail, cheat (don’t ask me how, just do it)</p>
<p>You can’t use trig properties if it’s not a right triangle.</p>
<p>Use the Law of Cosines to find the first side, then the Law of Sines to find the others. </p>
<p>Alternatively, using only Heron’s formula: Find the area, then use the equation A = absin(theta), where theta is the angle in between sides A and B.</p>
<p>This might be helpful: Let’s say the sides of the triangle are a, b, c in order from least to greatest. That means that the angles(in order from least to greatest) are opposite a, opposite b, opposite c. So if they gave you the sides and asked for the largest angle, it would be the angle opposite the longest side.</p>
<p>If this is a psat or sat question, you will only see a special triangle: 30-60-90, 45-45-90, or a 60-60-60. Otherwise, you can’t do such a question without some trigonometry, which isn’t on either test.</p>
<p>Okay, this is getting out of hand.</p>
<p>The SAT does not test students on Heron’s Formula or any Trig.</p>
<p>ahem…yeah…no trig on sat…</p>
<p>as i figure, if you’re starting to get that complicated, you’re overthinking the problem. start over after taking a few deep breaths.</p>
<p>choklitrain’s tip was very well taken.</p>
<p>there was such a question on the wed. psat.</p>
<p>Law of Cosines</p>
<p>well, SAT 1 still doesn’t req. those trig for m problems.
usually its 30-60, or 45 45 triangles. or at most, it tests u ur knowledge of the longer side,bigger angle,that type of Q. im not surprised that it appeared on a PSAT because it appeared in Oct 07 if my memory serves me right. this type of prob reqs no trig,but lil knowledge of properties; in other words, common sense.~</p>
<p>You need trigonometry to find the angles ,if you know the sides.</p>
<p>true^,but not in SAT1</p>
<p>btw, the easiest thing would be to simply take the arctan of the shortest sides, and then use the law of sines.</p>