Question
The diagram shows some land in the shape of a triangle ABC.
Houses are built on this land.
Each house requires 400 m² of land.
Find the greatest number of houses that can be built on this land.
▶️ Answer/Explanation
Solution
Ans: 1150
First calculate triangle area: ½ × 800 × 2300 × sin30°
sin30° = 0.5, so area = ½ × 800 × 2300 × 0.5 = 460,000 m²
Number of houses = Total area ÷ Area per house
460,000 ÷ 400 = 1,150 houses
Question
The diagram shows a trapezium.
The area of the trapezium is \(42cm^{2}\)
Calculate the value of x.
▶️ Answer/Explanation
Solution
Ans: 4.5
Area of trapezium = ½ × (sum of parallel sides) × height
42 = ½ × (9.5 + x) × 6
42 = 3 × (9.5 + x)
14 = 9.5 + x
x = 4.5 cm