Hello Jade,
Great, now we can solve this problem. Since we are dealing with an opposite and adjacent angle, with regard to the 54 degree angle, this makes is a tangent ratio. SOH - CAH - TOA
We can set up and solve the following equation.
tan 54 = x/12 Use a calculator or chart to find the tangent of 54
1.37 = x/12 Multiply by 12
16.44 = x
The length of the missing side x is 16.44.
I hope this helps,
MrEQ
