The change from one number to the next in a geometric sequence is called the

The change from one number to the next in a geometric sequence is called the common ratio

An angle of depression is measured from the horizon downwards and an angle of elevation is measured from the horizon upwards.

When solving for the sides or angles of a right triangle you can use trigonometry. The sine of an angle is found by the ratio of the opposite side and the hypotenuse. The cosine of an angle is found by the ratio of the adjacent side and the hypotenuse. The tangent of an angle is found by the ratio of the opposite side and the adjacent side.

The opposite side is always the leg opposite the angle that you are using. The adjacent side is the leg that forms one of the sides of the angle you are talking about and the hypotenuse is always across from the right angle.

If you know two lengths you can find the third leg length by using the Pythagorean Theorem.