Question: can you explain this question visually the answer is b...

Can you explain this question visually? The answer is b) but I don't understand why.

2.7 Given G-20a, + 50a, + 40a,, at (1, π/2, π/6) the component of G perpendicular to surface θ π/2 is (a) 20a, (b) 50a0 (c) 4