<p>Test 2, section 9, #12, i dont get at all. i feel pretty stupid because this is the only question i got wrong (i left it blank) in the whole section and it is supposed to be medium difficulty. </p>
<p>In the figure above, ABCD is a rectangle with BC = 4 and AB = 6. Points P, Q, and R are different points on a line (not shown) that is parallel to AD. Points P and Q are symmetric about line AB and points Q and R are symmetric about line CD. What is the length of PR?</p>
<p>I had no idea. I don't have a picture, but it's easy to visualize. Can someone help?</p>
<p>I got 8. If the points are symmetrical about a line, that means the distance from one point to the line is equal to the distance from the other point to the line. Let's call the distance from P or Q to their line "A," and the distance from Q or R to their line "B." Thus, the total distance PR will be 2A + 2B.</p>
<p>2A + 2B = ???</p>
<p>Okay, now divide it in half. You know that the width of the rectangle is 4, so the distance from Q to its line PLUS the distance from Q to the other line is exactly half of PR. This length is the same length as the rectangle (4).</p>