Please help me with physics?

Vector G :
x-component = 40.3 cos(-35°) m
y-component = 40.3 sin(-35°) m

Vector H:
x-component = 63.3 cos(270°) m
y-component = 63.3 sin(270°) m

Vector sum of vectors G and H :
x-component = 40.3 cos(-35°) + 63.3 cos(270°) m
y-component = 40.3 sin(-35°) + 63.3 sin(270°) m

Magnitude of the vector sum of vectors G and H
= √{[40.3 cos(-35°) + 63.3 cos(270°)]² + [40.3 sin(-35°) + 63.3 sin(270°)]²} m
= √{[40.3 cos35° + 0]² + [-40.3 sin35° - 63.3]²} m
= 92.5 m

...
I'll use my vector capable calculator

[40.3 m , -35.0°] + [63.3 m , 270°] = [92.5 m , 290.9°] or [92.5 m , -69.1°]

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Find the x- and y-components of each vector. You should know how to do this from trig. Then add them up to get x- and y- component of vector sum.
The magnitude of the resultant is simply the square root of sum of squares of those, which you should know from Pythagoras.

Gx + Hx = 40.3*cos(-35°) + 63.3*cos(270°) = 33.012 m
Gy + Hy = 40.3*sin(-35°) + 63.3*sin(270°) = -86.415 m
sqrt(33.021^2 + 86.415^2) = 92.5 m