Nicala's Blog

in chapter nine section 3

law of sine
you used the law of sine with non-right triangles and only when you know the angle and opposite leg's value.

formula
sin(angle)over its opposite leg= sine(angle two) over its opposite leg
you cross multiply to solve
A engineer wants to determine the distance between point A and point C. She knows that AB=25 angle A=110 and angle B=20. Find AC and BC.

first you HAVE to draw the triangle so you can solve it otherwise it will be very hard to visual what the triangle looks like.

you need to subtract the two angles away from 180.
180-110-20=50
then you but it in the formula
sin50 over 25=sin120 over AC
ACsin50=25sin20
AC=25sin20 overs sin 50
AC=11.2