Which direction are positive angles measured?

Positive angles are measured counterclockwise from the positive x-axis in the standard position of angle measurement. This convention is widely used in mathematics, particularly in trigonometry and geometry. When an angle is drawn starting from the x-axis and moving in the counterclockwise direction, it is considered a positive angle. For example, if you were to draw a 90-degree angle starting at the positive x-axis and moving counterclockwise, you would end up at the positive y-axis. This method aligns with the unit circle, where the angles are typically defined, making it easier to determine sine, cosine, and other trigonometric functions based on their positions related to the axes.

In contrast, measuring angles clockwise would result in negative angles, which are typically denoted as such. The other options, such as measuring angles horizontally or diagonally, do not align with standard practices in geometry and do not accurately describe the convention for measuring positive angles.