We can see that it is an enlargement but note that the question asks for the transformation from T to U.
Triangle U is clearly larger than Triangle T, so it is an enlargement by a scale factor greater than 1.

Draw three construction lines from vertices on Triangle U to corresponding vertices on Triangle T, as in the diagram below. Where the three lines intersect is the centre of enlargement.

cie-igcse-2018-may-jun-tz3-p2-q26a

The centre of enlargement is (7, 0).

The scale factor of enlargement is $\frac{distance from image (U) to centre}{distance from object (T) to centre}$ . We can measure these distances along the $x$ - and $y$ - axes. For example, from the top right vertices of U (5, 6) and T (6,3);

$\frac{x distance from (5, 6) to (7, 0)}{x distance from (6, 3) to (7, 0)} = \frac{2}{1} = 2 and \frac{y distance from (5, 6) to (7, 0)}{y distance from (6, 3) to (7, 0)} = \frac{- 6}{- 3} = 2$

"Enlargement about (7, 0), scale factor 2"

"enlargement" [1]
correct centre [1]
correct scale factor [1]

Transformations (Cambridge O Level Maths)

Exam Questions