Solving 2 unknown variables with 2 equations

[sami23]

Homework Statement

Find F and $$\theta$$

Homework Equations

Fcos$$\theta$$ = 250
Fsin$$\theta$$ = 420

The Attempt at a Solution

I can't remember how to solve 2 equations with 2 unknowns and trig functions... How do I start?

 

[ystael]

What trigonometric identities do you know that connect the sine and cosine functions?

 

[sami23]

sin²($$\theta$$) + cos²($$\theta$$) = 1