<p>In triangle PQR, PQ=4, QR= 3, PR=6, and the measure of angle PQR is x degrees. Which of the following MUST be true about x?</p>
<p>a) x=60
b) x=90
c) x>90
d) x<90
e) x is between 45 and 60</p>
<p>momofsky, this math problem is actually quite easy because believe it or not, there is no actual calculation involved! To solve the problem, you have to first know that a triangle with sides 3-4-5 is a right triangle. If you draw it out like the way it’s described but with PR=5, you can see that in this hypothetical case, angle PQR is 90 degrees. Now draw the triangle with PR=6, and you can see that angle PQR has to be >90 in order for the three sides to fit together.</p>
<p>If you want to take the trouble to do some calculations, you can also solve the problem using the [Law</a> of cosines](<a href=“http://en.wikipedia.org/wiki/Law_of_cosines]Law”>Law of cosines - Wikipedia), but I personally think that takes way too much effort.</p>
<p>Hope that helped :)!</p>
<p>thanks! That’s how I reasoned it out but it seemed way too simple.</p>