When a rocket engine fires at an angle, it forms the hypotenuse of a right triangle. We must use Trigonometry to map the engines' raw power into standard $X$ and $Y$ coordinates.
Any angled vector can be perfectly mapped to a flat $X/Y$ graph using the three fundamental trigonometric ratios: Sine, Cosine, and Tangent. You likely remember the mnemonic SOH CAH TOA from geometry class.
In aerospace, the Hypotenuse is the total raw power coming directly out of the rocket nozzle. The angle $\theta$ (theta) is the rocket's pitch angle relative to the ground.
If we want to know how much thrust is pushing horizontally across the ground (the Adjacent side), we simply multiply the raw thrust by the $\cos(\theta)$. If we want to know how much thrust is pushing vertically into the sky (the Opposite side), we multiply the raw thrust by the $\sin(\theta)$.
A SpaceX Falcon 9 booster is producing exactly $7,600\text{ kN}$ of raw thrust in a vacuum.
The flight computer has pitched the rocket sideways to exactly $30^\circ$ relative to the horizon.
Calculate exactly how much of that thrust is keeping the rocket from falling ($F_y$),
and how much is building orbital speed ($F_x$).
Conclusion: By pitching over to 30 degrees, the Falcon 9 is dedicating 86.6% of its engine power to building orbital speed, and reserving exactly 50% to fight gravity. Note that $3800 + 6581 \neq 7600$; vector components geometrically add via the Pythagorean theorem ($a^2 + b^2 = c^2$), not simple addition!