Video narration
How can a ramp's angle tell you its height? Imagine looking at a ramp from the side. The ground, the vertical rise, and the sloping ramp form a right triangle. The angle we choose is where the ramp meets the ground. From that angle, the rise is opposite, the ground-level run is adjacent, and the sloping length is the hypotenuse. Sine compares opposite with hypotenuse: opposite divided by hypotenuse. Cosine compares adjacent with hypotenuse; tangent compares opposite with adjacent. Opposite and adjacent are named relative to the angle you chose. These aren't three unrelated rules. Each ratio connects a known side to the side you want. For the ramp, assume you know its sloping length and the angle it makes with the ground. Then the rise is that length multiplied by the sine of the angle.