Chapter 9 cont'd

So this week we pretty much wrapped up chapter nine from last week. We basically spent this week in review for our exams. This is seventh hour so I think (by think i mean pretty sure, almost positive) our exam is Thursday. This means that we have a little extra time to catch the hang of anything you don't have completely down packed by now.
As usual the chapter opens with the more easier subjects. 9-2 consists of finding the area of triangles. This hater is relatively simpler than the other sections because it has a rather simple formula that is quite easy to
remember:
( 1/2bh )for right triangles.
( 1/2ab(sin(angle btwn)) for non right.

Section 9-3 illustrates the law of sines.
This formula can only be used with non right triAngles. * it can only be used when you have the angle opposite leg identified.
( sin (angle) ) / opp leg = ( sin ( angle2) / opp leg 2
To solve cross multiply and divide.

If you have neither paired sides/Angles you have to use Another formula which acts as a last resort. The lA of Cosines is used when you are looking for the area of non right triAngle Nd you do not have a pair.

Opp leg^2= adj leg^ 2 +adj leg^2 - 2(adj leg)(adj leg)cos(angle btwn)

Example:
a.5 in b.2 in ang.C 35

To find area of this nonright triangle use the formula 1/2ab sine(ang)
1/2(5)(2) sin(35)
* enter in calc as in ( in degree mode )

Answer:2.87 inches squared
* area is always squared!

:)