Worked Solution & Answer
220 m2
Home > Maths quizzes > Grade 4 Quizzes > Surface area
Grade 4 • 4N • 10 Questions (30 Marks)
Explanation:
The total surface area of a 3D solid is the sum of the areas of all its outer faces, measured in square units (cm² or m²). A cuboid has 6 rectangular faces in 3 identical opposite pairs: Surface Area = 2(lw + lh + wh).
For a triangular prism, add the areas of the 2 triangular ends (12 × base × height each) and the 3 rectangular sides. Be careful not to confuse the slant edge of the triangle with its perpendicular height!
Example 1: Find the total surface area of a cuboid measuring 8 cm by 5 cm by 3 cm.
Example 2: A right-angled triangular prism has ends 3 cm, 4 cm, 5 cm and length 10 cm. Find its total surface area.