This week we went over section 9.1 which talked about right triangles. Some easy ways to remember your formulas is by remembering SOHCAHTOA.

sin(theta)=opposite/hypotenuse
cos(theta)=adjacent/hypotenuse
tan(theta)=opposite/adjacent
csc(theta)=hypotenuse/opposite
sec(theta)=hypotenuse/adjacent
cot(theta)=adjacent/opposite

You only use these functions when you are trying to deal with right triangles. The hypotenuse is the opposite of the right angle.

Ex.

For the triangleABC find the value of b to 3 significant digits

opp leg= 40 degrees

adj leg=?

b tan 28 (degrees)= 40/b

b tan28(degrees)=40

b= 40/tan28=

b=75.2 degrees