Answer:
12.7
Step-by-step explanation:
12.7
Basically u are gonna wanna use pythagoras first
BC = √(12^2 - 6^2) = √(144 - 36) = √(108) = 10.39230485
Also the Side Angle Side rule comes into play use the following
BC/sin(55) = CD/sin(90) <----- angle
BC/sin(55) = CD/sin(90)
sin(90)BC/sin(55) = CD
1*BC/sin(55) = CD
BC/sin(55) = CD
10.39230485/0.819152044 = CD
12.68666167 = CD
12.7 = CD
