1. **State the problem:** We have three angles around a point. Two angles are given as 113° and 51°. We need to find the third angle and classify it. 2. **Formula and rule:** The sum of angles around a point is always 360°. So, $$\text{Angle}_1 + \text{Angle}_2 + \text{Angle}_3 = 360^\circ$$ 3. **Calculate the third angle:** $$\text{Angle}_3 = 360^\circ - (113^\circ + 51^\circ)$$ $$= 360^\circ - 164^\circ$$ $$= 196^\circ$$ 4. **Classify the third angle:** - An **obtuse angle** is between 90° and 180°. - A **right angle** is exactly 90°. - An **acute angle** is less than 90°. - A **reflex angle** is between 180° and 360°. Since $196^\circ$ is greater than 180° but less than 360°, the third angle is a **reflex angle**. **Final answers:** - a) The third angle is $196^\circ$. - b) The third angle is a reflex angle.