Area & Volume of 3D Objects
Surface area and volume of prisms
Surface Area and Volume of Prisms
A prism is a 3D shape with the same cross-section throughout. Volume = area of base × height. Surface area = sum of areas of all faces. Common prisms: rectangular prism (box) and triangular prism.
Example
Rectangular Prism (Box)
Length = 5 cm, width = 3 cm, height = 4 cm.
Volume = l × w × h = 5 × 3 × 4 = 60 cm³
Surface area = 2(lw + lh + wh)
= 2(15 + 20 + 12) = 2(47) = 94 cm²
Example
Triangular Prism
Base triangle: base 6 cm, height 4 cm. Prism length: 10 cm.
Area of triangular base = ½ × 6 × 4 = 12 cm²
Volume = 12 × 10 = 120 cm³
Note
Remember
Volume is in cubic units (cm³, m³). Surface area is in square units (cm², m²). Volume = base area × perpendicular height. Surface area = sum of all the flat faces.
Key Vocabulary
PrismA 3D shape with a uniform cross-section
VolumeThe space inside a 3D object (cubic units)
Surface areaThe total area of all faces of a 3D object
Cross-sectionThe shape you see when you slice through a 3D object
FaceA flat surface of a 3D shape
SASL Avatar
Loading avatar...
1 / 5
Prism
Speed: