10.2.1 Transformations II, PT3 Focus Practice

10.2.1 Transformations II, PT3 Focus Practice

Question 1:
In the diagram, ∆P’Q’R’ is the image of ∆PQR under an enlargement.

(a) State the scale factor of the enlargement.
(b)   If the area of ∆PQR = 7 cm2, calculate the area of ∆P’Q’R’.

Solution:
(a)

(b)
Area of image = k× Area of object
Area of ∆P’Q’R’ = 22 × 7
= 28 cm2

Question 2:
In diagram below, OP’Q’ is the image of OPQ under an enlargement with centre O.

Given PQ = 4cm, calculate the length, in cm, of P’Q’.

Solution:

Question 3:
In diagram below, PQ’R’S’ is the image of PQRS under an enlargement.

Calculate the length, in cm, of SS’.

Solution:

Question 5:
In diagram below, quadrilateral AFGH is the image of ABCD under an enlargement.

(a) Find the scale factor of the enlargement.
(b) The area represented by the quadrilateral AFGH is 15cm2. Find the area, in cm2, represented by the shaded region.

Solution:
(a)
$\begin{array}{l}\text{Scale factor}\\ =\frac{3}{6+3}=\frac{3}{9}=\frac{1}{3}\end{array}$

(b)
Area of image = k× Area of object