October 09, 2006


Sorry for taking so long guys! I was busy this weekend with volleyball and thangksgiving. Happy Thanksgiving by the way! Okay now down to business. Heres my scribe post. Not Much but at least its somthing!

Okay so we did 2 questions in class on Friday:

1. How many triangles, ABC, are possible with a=4, b=7 and angle A=30 degrees?

For most people, drawing the picture first helps out a lot, so here is one possibility:

Now you can figure out sinB because you know 2 sides and 1 angle. Heres how:
sin30/4 = sinB/7
sinB = 7sin30/4
sinB = 0.875

To find the angle, on you're calculator you do inverse sine of 0.875.
angle B = 61 degrees

You know you can make a triangle with that because you know 2 angles and when you add them they do not add up to 180 which makes it possible to have another angle.

The calculator only gives you the angle in quadrant I but there can also be an angle in quadrant II which you can figure out by taking the angle you got and subracting it from 180.

In this case, angle B can also = 119 degrees. Therefore, you can make 2 triangles.

THE NEXT SCRIBE IS.. NATNAEL!! (sorry for taking so long)

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