<p>Hi everyone,</p>
<p>I am going through all the chapters in the Kaplan SAT Maths Level 2 Prep Book and can't figure out what I am doing wrong at one problem. It's in Chapter 6, Solid Geometry, the very last problem with the pyramid (follow up test). I usually have no problems with geometry and also managed to get all (except for this one) examples right. I've been fighting for the last 20 minutes. </p>
<p>The concept behind the solution is simple, just apply pythagoras, some of the "special" triangle knowledge and it should be no problem. Following are my calculations: (I find using the calculator easier than doing it all by hand (partial roots and that stuff) in this problem)</p>
<ol>
<li>step: find diagonal:</li>
</ol>
<p>it's sqrt(4^2+4^2) = sqrt(16+16) = sqrt(32)</p>
<ol>
<li><p>step half of the diagonal = sqrt(32)/2</p></li>
<li><p>h= sqrt(4^2-(sqrt(32)/2)) --- I use the value from above^^</p></li>
<li><p>find volume: 4^2*h/3</p></li>
</ol>
<p>my result is: 19.3560862 if I enter the steps from above into my calculator. Kaplan says it's 15.08 </p>
<p>I totally understand the way they suggest I solve the problem- keeping the roots and stuff, but I prefer working with the calc (i have a ti84 se) on these problems because I am faster...</p>
<p>Maybe someone can help me there, it really annoys me...</p>
<p>Best,
mrmaster</p>