Answer: (n-2) × 180°.
- A (n-2) × 180°
- B n × 90°
- C (n-1) × 180°
- D n × 180°
Correct answer: A. (n-2) × 180°
Explanation: Sum of interior angles = (n-2) × 180°. For triangle n=3: 180°. Quadrilateral n=4: 360°.
Three standard 3D solids and their key formulas: a cylinder's volume scales with the full height, a cone's volume is exactly one-third of the cylinder with the same base and height, and a sphere's volume and surface area both follow distinct r-based formulas worth memorising separately.
Concept context
Perimeters, areas, and volumes of 2D and 3D shapes