1. **Problem statement:** Calculate the angles corresponding to the decimal fractions in a semicircle diagram. 2. **Formula:** The total angle in a semicircle is $$180^\circ$$. To find the angle for each fraction, multiply the fraction by $$180^\circ$$: $$\text{Angle} = \text{Fraction} \times 180^\circ$$ 3. **Calculations:** - For 0.4: $$0.4 \times 180^\circ = 72^\circ$$ - For 0.3: $$0.3 \times 180^\circ = 54^\circ$$ - For 0.2: $$0.2 \times 180^\circ = 36^\circ$$ - For 0.1: $$0.1 \times 180^\circ = 18^\circ$$ 4. **Explanation:** Each decimal fraction represents a part of the semicircle. Multiplying by 180 degrees converts the fraction into the corresponding angle measure. **Final answers:** - Angle for 0.4 is $$72^\circ$$ - Angle for 0.3 is $$54^\circ$$ - Angle for 0.2 is $$36^\circ$$ - Angle for 0.1 is $$18^\circ$$