Week 17- precalc 11

This week in pre calc we reviewed the idea of trigonometry and then learned new things to add on to what we already knew.

So one of the things that we learned was the SIN LAW.

The sin law is


The lower case letters are the side length measurements and the upper case letters are the angles degrees.

Because the Sine Law works with the angles of triangles and the measurements of the triangles side then it’s useful in finding a missing angle or side.

how to use the sin law:




step 1: fill in what you know from the image

sinA/a = sinB/b = sinC/c

sinA/5 = Sin80/7 =sinC/c

and then u would take the two that has the most information/ what your looking for

in this case it would be sinA/5 = sin80/7

because were trying to find angle A

so we would next solve the equation

sinA = 5sin80/7

A=sin-1 (5sin80/7)

A= 44.7

and now you know what angle A is.

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