Question

Use a graph paper for this question.
(i) The point P (2, – 4) is reflected about the line x = 0 to get the image Q. Find the coordinates of Q.
(ii) Point Q is reflected about the line y = 0 to get the image R. Find the co-ordinates of R.
(iii) Name the figure PQR.
(iv) Find the area of figure PQR.

Answer 1

(i) P (2, – 4) is reflected in (x = 0) y-axis and Q-image.
\[\ce{P(2, -4) ->[My][]Q(-2, -4)}\]

(ii) Q (-2, -4) is reflected in (y = 0) x-axis to get R.
\[\ce{Q(2, -4) ->[Mx][]R (-2, -4)}\]

(iii) The figure PQR is right triangle as shown ahead:

(iv) Area of ΔPQR = `(1)/(2) xx "PQ" xx "QR"`
= `(1)/(2) xx 4 xx 8`
= 16 sq. unit.