Kaitlyn's Blog #7

In this blog, i will be going over section 9-4.


This section was easy for me. All you have to do is plug your information into the formula and solve. In this section we learned about the Law of Cosines. This is used when you dont have a pair in a non right triangle.

Formula: opp leg(squared)=adj leg(squared) + adj leg(squared) - 2 (adj leg)(adj leg)

cos(angle b/w)

Example: a non right triangle has sides 5cm and 3cm. The angle between those sides is 50.

First you need to sketch out the triangle to see what you have to work with. You want to find the other side of the triangle. To do this you must plug your information into the formula.

x(squared)=5(squared) + 3(squared) - 2(5)(3) cos(50)
Square root everything to get:
x=[square root of] 5(squared) + 3(squared) - 2(5)(3) cos (50)

Plug this into your calculator exactly as shown and your answer comes out to be: x=3.836 cm^2

This is what i learned form Section 9-4...