Helen's Blog #6

I'll be going over section 9-1.

*Always remember SOHCAHTOA

Sin(theta)=opp/hyp
Cos(theta)=adj/hyp
Tan(theta)=opp/adj
Csc(theta)=hyp/opp
Sec(theta)=hyp/adj
Cot(theta)=adj/opp

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

Example:

In Triangle ABC, Angle A= 90 degrees, Angle B= 25 degrees, and a= 18, Find b and c.

To find b you would use:
sin 25= b/18

b= 18sin25
= 7.607

To find c you would use:
cos25=c/18

c=18cos25
=16.314

In Triangle DEF, Angle D=90, Angle E= 12 degrees, and e=9. Find d and f.

To find f you would use:

tan12=9/f

f=9/tan12
=42.342

To find d you would use:

sin12=9/d

d=9/sin12
43.288