For class on Thursday, March 12, 2009

Please continue to solve the problems on page 496. Work with a partner or a group. I will post hints here as we go along.

Hints:

Problem 6 page 496: Graph it on geogebra like this. In the algebra window you will
find the answer!























#7 on page 496. There are two easy ways to solve this. Geogabra will solve it immediately if
you first create the triangle using the polygon function. Or remember the facts we learned about the 30-60-90 triangle on page 476:
"The 30-60-90 triangle conjecture: In a 30-60-90 triangle, if the shorter leg has length a, then the longer leg has length (a*square root of 3) and the hypotenuse has length of 2a."

So the area of this triangle is (1/2) times what times what?

8. If the area of the square is 144 then a side is 12. So the length of this diagonal is the same as solving this equation for d: 12^2 + 12^2 = d^2.

9. What makes this problem hard is we don't know the DC. I would just solve it on geobabra. Like this:










Can anyone figure out another way to do it?

10. The square root of 7^2 + 25^2 is the length of the diameter of the semi-circle. The formula for the area of a circle is 3.14*r^2. Can you solve the problem from there?