Nathan's Blog :(

In this blog, I will go over section 9-2, which involves the area of right and non-right triangles.

1/2 bh - only right triangles
1/2 ab sin(angle between) - only for non-right triangles

Ex. This is just a regular triangle. The left side is 7 and the right side is 4. The angle between them is 73 degrees. This is a non-right triangle.

A=1/2 ab sin(theta)
A=1/2(7)(4) sin73
A=14sin73
A=13.388 cm squared

Ex. 2 The area of triangle PQR is 15. p=5 and q=10. Find all possible measures of angle R.

Draw a regular triangle. (There's an A word that B-Rob calls it but I can't remember.)
Bottom left point=P; Top point=Q; Bottom right point=R

15=1/2(5)(10) sin (theta)
15=25 sin (theta)
sin(theta)=15/25
(theta)=sin^-1(15/25)
(theta)=36.870 degrees

36.870 is in the first quadrant. Sin is positive in Q I and II.
-36.870+180=143.130 degrees.

So theta=36.870 degrees and 143.130 degrees.

That's about it. I agree with David on his Week 5 Blog Prompt. Now I can enjoy my weekend.