The points P (1,-1 ), Q ( 4,-1) and R ( 4, 3) are reflected in y-axis. If the images are denoted byP' , Q' , and R' , then
(i) Find the co-ordinates of P'Q'R' , Q' and R'
(ii) What kind of figure is formed by RR' Q' Q?
(iii) Find the perimeter of the figure P'Q'R'
Solution
(i) Find the co-ordinates of P'Q'R' , Q' and R'
The co-ordinates are: P'Q'R' = (-1,-l );Q' = (-4,-l );R' = (-4, 3)
(ii) What kind of figure is formed by RR' Q' Q?
A rectangle is formed by RR' Q' Q.
(iii) Find the perimeter of the figure P'Q'R'
The figure is a right angled triangle with sides 4 units, 3 units and 5 units.
Here, height= 4 units, base = 3 units and
Hypotenuse = `(sqrt 4^2 + 3^2)`
= `sqrt (16 + 9)`
= `sqrt 25`
= 5 units
Perimeter = height+ base + hypotenuse
= 4 + 3 + 5
= 12 units
