1. **Problem statement:** The area of triangle PQR is 20 cm², with sides |PQ| = 10 cm and |PR| = 8 cm. We need to find the two possible values of the angle |∠QPR|. 2. **Formula used:** The area of a triangle given two sides and the included angle is $$\text{Area} = \frac{1}{2}ab\sin C$$ where $a$ and $b$ are the sides and $C$ is the included angle. 3. **Apply the formula:** Here, $a = 10$, $b = 8$, and area = 20. $$20 = \frac{1}{2} \times 10 \times 8 \times \sin \theta$$ 4. **Simplify:** $$20 = 40 \times \sin \theta$$ Divide both sides by 40: $$\frac{20}{40} = \cancel{40} \sin \theta / \cancel{40}$$ $$\sin \theta = 0.5$$ 5. **Find possible angles:** Since $\sin \theta = 0.5$, the possible angles in degrees between 0° and 180° are $$\theta = 30^\circ \text{ or } 150^\circ$$ 6. **Answer:** The two possible values of $|\angle QPR|$ are $30^\circ$ and $150^\circ$.