Answer: (a + b + c)/2.
- A a + b + c
- B (a + b + c)/2
- C abc
- D a + b
Correct answer: B. (a + b + c)/2
Explanation: s is the semi-perimeter = (a+b+c)/2.
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