<p>Can anyone explain numbers 44, 45, and 57 from the ACT practice test at <a href="http://media.act.org/documents/preparing.pdf%5B/url%5D">http://media.act.org/documents/preparing.pdf</a> to me?</p>
<ol>
<li><p>I don't understand how it is not 4 lines of symmetry... One through each pair of facing triangles are the only lines I see. How are there 8?</p></li>
<li><p>Area = Pi * Radius^2
Area = 3.14 times 4
E. right?
How is it 3.1?</p></li>
<li><p>Just didn't know how to go about it.</p></li>
</ol>
<p>Oh and I don’t understand 38.</p>
<p>well, I’ll take the easy one first:</p>
<ol>
<li><p>the radius should be 1 in your equation,
not 2 (the diameter)</p></li>
<li><p>The lines of symmetry - pretend you have
a (0,0) center point in the middle of the picture and
have a x-y coordinate system drawn. The lines of symmetry would be
lines at 0 degrees, 30 degrees, 45, 60, 90, 120, 135, and</p></li>
<li><p>(meaning - take your protractor and drawn lines at these
degrees and you can see that the stained glass is symmetrical
on both sides on the line)</p></li>
</ol>
<ol>
<li> They give you the formula in the question (law of cosines), so you
just plug the numbers from the picture in and I think E) would then
be the answer. It doesn’t matter that the pictures says A for the angle
and the equation says C. Just re-label them. As long as you keep the
right opposite number with the right label.</li>
</ol>
<p>For 38. draw an imaginary line right down the middle of the picture and
you can see that the white part is 1/4 of the shaded part in each half,
so the ratio would be 1:4. You can’t always just go by the picture,
but they state that those points are midpoints.</p>
<p>Thanks for the help! I missed most of these because of careless mistakes but I still do not understand the lines of symmetry. I see eight distinct points to run lines of symmetry through but each line hits two points so I can only find four lines. I am only finding lines the point of each triangle. Since there are 8 triangles and each line hits two points, I am finding four lines. What am I missing?</p>
<p>not sure if I’m explaining it right - but you have the lines at the top point of the triangles, but also the lines inbetween (where one triangle touches the next triangle).</p>
<p>jbourne is wrong about number 38</p>
<p>The answer is G, so the ratio is 1:3, not 1:4.</p>
<p>doh! thanks for the correction</p>