Computing Actual Areas from a Scale Drawing

__________: A ratio between the measurements of the drawing and of the actual object.

• scale drawing

• constant of proportionality

• scale

• unit rate

Determine the scale in the form of 1:n

Determine the scale used in the form of 1:n

Sarah draws a scale drawing of an object using certain scale. It is found that the scale drawing is bigger than the object. Which of the following is possible scale used by Sarah?

• 1 : 1

• 1 : 2

Find the perimeter of the large triangle.

• 24
• 36
• 12
• 54

A house plan is drawn with the scale of 1:400. The length and the width of living room on the plan are 5cm and 4cm respectively. If the living room is shape of a rectangle, what is the actual area, in m², of the living room?

• 20

• 320

• 200 000

• 3 200 000

The actual area of a square garden is 400m². If the garden is drawn using the scale of 1:500, calculate the area, in cm², of the drawing.

• 4

• 8

• 16

• 20

The diagram shows a combination of a rectangle JKMN and a triangle KML. If the measurement of the scale drawing of KL is 6.5cm, what is the scale for the drawing?

• 1 : 2

• 1 : 20

• 1 : 200

The diagram is redrawn using the scale of 1:200. Calculate the length of AB, in cm, of the drawing.

• 2.5

• 3

• 5

• 6

The actual length of a side of a quadrilateral is 49mm. The length of the mentioned side on a scale drawing is 7cm using the scale of 1:n. Calculate the value of n.