Volume of prisms
Find the volume of rectangular and triangular prisms, and solve capacity and composite prism problems.
Worked examples
Volume of a rectangular prism
Straightforward
Problem
A rectangular prism has length , width and height . Find its volume.
1
Write the volume formula for a rectangular prism.
2
Substitute the known dimensions.
3
Multiply to find the volume.
Answer
Volume of a triangular prism
Moderate
Problem
A triangular prism has a right-angled triangular cross-section with base and perpendicular height . The prism is long. Find its volume.
1
Find the area of the triangular cross-section.
2
Multiply the cross-sectional area by the length of the prism.
Answer
Volume of a tank and capacity
Challenging
Problem
A rectangular water tank is long, wide and deep. Water fills of its capacity. How many litres of water are in the tank? ()
1
Find the full volume of the tank using .
2
Find the volume of water, which is of the full volume.
3
Convert from to litres by dividing by .
Answer
Practise
Q1·Straightforward
A rectangular prism has length , width and height . Find its volume in .
Explanation
Q2·Straightforward
A rectangular prism has length , width and height . Find its volume in .
Explanation
Q3·Straightforward
A rectangular prism has length , width and height . Find its volume in .
Explanation
Q4·Straightforward
A rectangular prism has length , width and height . Find its volume in .
Explanation
Q5·Moderate
A triangular prism has a right-angled triangular cross-section with base and perpendicular height . The prism is long. Find its volume in .
Explanation
Area of cross-section: . Volume:
Q6·Moderate
A triangular prism has a right-angled triangular cross-section with base and perpendicular height . The prism is long. Find its volume in .
Explanation
Area of cross-section: . Volume:
Q7·Moderate
A triangular prism has a right-angled triangular cross-section with base and perpendicular height . The prism is long. Find its volume in .
Explanation
Area of cross-section: . Volume:
Q8·Moderate
A triangular prism has a right-angled triangular cross-section with base and perpendicular height . The prism is long. Find its volume in .
Explanation
Area of cross-section: . Volume:
Q9·Challenging
A prism has an L-shaped cross-section formed by joining a rectangle and a rectangle. The prism is long. Find its volume in .
Explanation
Area of L-shape: . Volume:
Q10·Challenging
A rectangular water tank is long, wide and deep. Water fills of its capacity. How many litres of water are in the tank? ()
Explanation
Full volume: . Water: . In litres:
Q11·Challenging
A building has a cross-section made up of a rectangle wide and tall, topped by a triangle wide and tall. The building is long. Find the total volume in .
Explanation
Rectangular area: . Triangular area: . Total cross-sectional area: . Volume:
Q12·Challenging
A concrete ramp has a trapezoidal cross-section with parallel sides of and , and a perpendicular width of . The ramp is long. Find the volume of concrete in .
Explanation
Area of trapezium: . Volume: