Rigid transformations and angles

Practice sheet

Fresh questions from the whole chapter, to do on paper.

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  1. Put the steps for constructing the perpendicular bisector of a segment AB of length 7 cm in order.
    • With the compass point on A, draw an arc with a radius of more than half of AB
    • Keep the same opening; with the point on B, draw an arc that crosses the first one twice
    • Label the two crossing points P and Q
    • Draw the line through P and Q with the straightedge
  2. In the construction of the perpendicular bisector of AB (AB = 10 cm), why does the line PQ through the two arc crossings bisect AB at a right angle?
    1. P and Q are each as far from A as from B, and such points lie on the perpendicular bisector
    2. Because the angle measures 90° with a protractor
    3. Because the arcs have a radius of 10 cm
  3. To inscribe a regular hexagon in a circle of radius 8 cm, you step the compass around the circle. Which opening do you keep?
    1. 8 cm, the radius of the circle
    2. 16 cm, the diameter
    3. Any opening, as long as it never changes
  4. A regular hexagon is constructed inside a circle of radius 4 cm, with its vertices on the circle. What is its perimeter, in cm?Not to scale
  5. Translate the point A(−4,−4)A(-4, -4) by 2 units right and 1 units down. Tap its image A′A'.
  6. A translation takes (−3,0)(-3, 0) to (0,5)(0, 5). By how many units does it move points horizontally (positive = right)?
  7. A polygon with 9 sides is translated. What changes?
    1. Only its position: lengths and angles stay the same
    2. Its side lengths
    3. Its angles
  8. Translate triangle ABC 2 right and 2 down. Tap the images A′, B′ and C′.
  9. Reflect A(3,2)A(3, 2) across the xx-axis. Tap its image.
  10. Reflect A(5,−1)A(5, -1) across the line y=xy = x. Tap its image.
  11. A point is 5 units from a line of reflection. How far is it from its image?
  12. Reflect triangle ABC across the yy-axis. Tap the images A′, B′ and C′.