6.1 Angles 6.1 Angles We will learn to recognize and name tapered angles and right angles in the shapes of rectangles, equal squares and triangles. Angle An angle is a shape formed by two lines that share the same endpoint, called the vertex of an angle. Angles provide a way to express the difference in gradient between two lines that meet at an angle without having to define the gradient of both. The unit of measurement for an angle is degrees (°). Angles can be divided into 3 types: Right Angle The right angle is at 90°. Acute Angle An acute angle is an angle whose value is less than 90°. Obtuse Angle An obtuse angle is greater than 90° but less than 180°.