The images to solve this problem is in the attachment.
Answer:
= 671.0 N;
= 300 N
Explanation: From the image in the attachment and knowing that the box is in equilibrium, i.e., the "sum" of all the forces is 0, it is possible to conclude that:
=
and
=
Using trigonometry, shown in the second attachment, the values for each force are:
sin 20° =
=
. sin(20)
= 735.0.913
= 671.0
cos 20° =
=
. cos (20)
= 735.0.408
= 300
The force of static friction is 671N and normal force is 300N