10 questions · Form 3 Mathematics Bab 3: Scale Drawings
If the scale of a map is 1 : 100, and a garden has an area of 5 cm² on the map, what is the actual area of the garden in square metres?
Prefer reading to quizzing? All 10 questions are listed below with the answer and explanation under each one.
1. If the scale of a map is 1 : 100, and a garden has an area of 5 cm² on the map, what is the actual area of the garden in square metres?
Answer: A
Actual Area = Drawing Area × n² = 5 cm² × (100)² = 5 × 10,000 = 50,000 cm². Converting to m²: 50,00010,000 = 5 m².
2. A map uses a scale of 1 : 50,000. If the distance between two towns on the map is 6 cm, calculate the actual distance in kilometres.
Answer: A
Actual distance = 6 cm × 50,000 = 300,000 cm = 3,000 m = 3 km.
3. A scale is given as 1 : 14. What is the length of the scale drawing if the actual length of the object is 8 cm?
Answer: B
Drawing Length = Object Length / n = 8 / (14) = 8 × 4 = 32 cm.
4. Which of the following grid transformations results in a scale drawing with scale 1 : 3?
Answer: A
A scale of 1 : 3 means every drawing dimension is 13 of the corresponding actual object dimension.
5. In a scale drawing with scale 1 : 20, the drawing area is 15 cm². What is the actual area in cm²?
Answer: B
Actual area = Area of drawing × n² = 15 × (20)² = 15 × 400 = 6,000 cm².
6. A cell length of 0.02 mm is drawn with a length of 4 cm. What is the scale of the drawing in the form 1 : n?
Answer: B
Convert 4 cm to mm = 40 mm. Scale ratio = Drawing : Object = 40 : 0.02 = 1 : (0.0240) = 1 : 0.0005 or 1 : 1200.
7. A bridge of actual length 150 m is drawn to a scale of 1 : 3,000. Calculate the length of the bridge on the drawing in centimetres.
Answer: A
Actual length = 150 m = 15,000 cm. Drawing length = 15,0003,000 = 5 cm.
8. The actual distance between two grid points is 25 km. On a map, this distance measures 5 cm. What is the scale of the map?
Answer: A
Actual distance = 25 km = 2,500,000 cm. n = 2,500,0005 = 500,000. Scale = 1 : 500,000.
9. What is the general ratio representation used for scale drawings?
Answer: B
Scale drawings are expressed in the form 1 : n, where 1 represents the drawing length and n represents the actual object length.
10. An object side of length 12 cm is represented by 3 cm on a drawing. What is the scale ratio 1 : n?
Answer: B
n = Object / Drawing = 123 = 4. Therefore, scale = 1 : 4.