Step-by-step explanation:

<span>Cougar population was 790 at the beginning
830-790=40</span>
This is only my opinion. I could be wrong.
My guess is:
Somebody else used that book before you, maybe last year or
the year before, and it was somebody who didn't mind writing
in his book.
One day he didn't have time to write down the homework in his
assignment notebook, so he just circled the homework problems
in his textbook.
<span>So the question is how to find the volume of a L-block geometrical body. To do that we need to turn an L-block into something we know how to calculate the volume. in the case of an L-block we can use two rectangles because we can calculate it's volume easily, as V=a*b*c and simply sum the two volumes. </span>
<span>Use a straightedge to join points W and P and then points P and X. â–łWPX is equilateral.
Let's see now, Delmar has a line segment WX and has drawn 2 circles whose radius is the length of WX, centered upon W and centered upon X. Sounds to me that all he needs to do is select one of the intersections of those 2 circles and use that at the 3rd point of the equilateral triangle and draw a line from that point to W and another line from that point to X. Doesn't matter which of the two intersections he chooses, just needs to pick one. Looking at the available options, only the 1st one which is "Use a straightedge to join points W and P and then points P and X. â–łWPX is equilateral." matches my description, so that is the correct choice. The other choices tend to do rather bizarre things like create a perpendicular bisector of WX and for some unknown reason, claim that bisector is somehow a side of a desired equilateral triangle.</span>