##
A scale drawing of an object is the same shape at the object but a different size. The scale of a drawing is a comparison of the length used on a drawing to the length it represents. The scale is written as a ratio. The ratio of two corresponding sides in similar figures is called the scale factor

Scale factor = length in image / corresponding length in object

If one shape can become another using revising, then the shapes are similar. Hence, two shapes are similar when one can become the other after a resize, flip, slide or turn. In the photograph below showing the side view of a train engine. Scale factor is 1:200

##
This means that a length of 1 cm on the photograph above corresponds to a length of 200cm or 2 m, of the actual engine.

The scale can also be written as the ratio of two lengths.

##
**
Question 1
**

##
If the length of the model is 11cm, then the overall length of the engine in the photograph above, including the couplings(mechanism used to connect) is:

(a) 22 cm

(b) 220 cm

(c) 220 m

(d) 22 m

##
**
Question 2
**

##
What will affect the similarity of any two polygons?

(a) They are flipped horizontally

(b) They are dilated by a scale factor

(c) They are translated down

(d) They are not the mirror image of one another.

##
**
Question 3
**

##
What is the actual width of the door if the width of the door in photograph is 0.35cm?

(a) 0.7 m

(b) 0.7 cm

(c) 0.07 cm

(d) 0.07 m

##
**
Question 4
**

##
If two similar triangles have a scale factor 5 : 3 which statement regarding the two triangles is true?

(a) The ratio of their perimeters is 15 : 1

(b) Their altitudes have a ratio 25 : 15

(c) Their medians have a ratio 10 : 4

(d) Their angle bisectors have a ratio 11 : 5

##
**
Question 5
**

##
The length of AB in the given figure:

(a) 8 cm

(b) 6 cm

(c) 4 cm

(d) 10 cm