2020 · Q95
Angles are shown in the given figure. What is value of angle1 + angle2 + angle3 + angle4 + angle5 + angle6 + angle7 + angle8?
Elementary MathematicsGeometry: Lines, Angles and Triangles
- A240°
- B360°
- C540°
- D720°
Explanation
Let the 8 marked angles be Aᵢ and the 4 central angles Cᵢ. In each triangle Aᵢ + Aⱼ + Cᵢ = 180°; over 4 triangles the sum is 720°. The central angles sum to 360°, so the 8 marked angles sum to 360°.