four forces act an object: 1000n at 0°, 80n at 90°, 50n at 180° and 20n at 270°. determine the net force

Answer 1

the forces are
<1000,0>, <0,80>, <-50,0>, <0,-20>
So, just add them up to get <950,60>
Why do I think 1000 is a typo?

Answer 2

Fn = 1000N[0o] + 80N[90o] + 50N[180o] + 20N[270o],
Fn = 1000 + 80i - 50 - 20i = 950 + 60i = 952N[3.60] = net force.