CHAPTER 16. GEOMETRY 16.6
- Show that the line x = k for any constant k is parallel to the y-axis. (Hint: Show that the
inclination of this line is 90 ◦.)
More practice video solutions or help at http://www.everythingmaths.co.za(1.) 0134 (2.) 0135 (3.) 0136 (4.) 0137
16.6 Transformations
EMBCO
Rotation of a Point EMBCP
When something is moved around a fixed point,we say that it is rotated about the point. What happens
to the coordinates of a point that is rotated by 90 ◦or 180 ◦around the origin?Activity: Rotation of a Point by 90 ◦
Complete the table, by filling in the coordinatesof the points shown in the figure.Point x-coordinate y-coordinate
A B C D E F G H�� � �
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D C B
E
F G H
What do you notice about the x-coordinates? What do you notice about the y-coordinates?
What would happen tothe coordinates of point A, if it was rotated to theposition of point C?
What about if point B rotated to the position of D?Activity: Rotation of a Point by 180 ◦
Complete the table, by filling in the coordinatesof the points shown in the figure.