Please help me!! How do I do this?

Answer:
Taking 45 degree as reference angle
Then using sine rule
sin 45=
p/h
replacing the value of sin 45 degree by 1/root 2.so
1/root 2=9/c
doing cross multiplication
9*root 2=1*c
9 root 2 =c
therefore the value of c is 9 root 2
Step-by-step explanation: