Answer:
21cm
Step-by-step explanation:
A scale drawing is a reduced form in terms of dimensions of an original image / building / object
the scale drawing is usually reduced at a constant dimension
scale of the drawing = original dimensions / dimensions of the scale drawing
12/9 = 1.333333
1 : 1.3333333
length of model sheep = 28 / 1.333333 = 21cm
