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Question
Using a graph paper, plot the points A(6, 4) and B(0, 4).
- Reflect A and B in the origin to get the images A' and B'.
- Write the co-ordinates of A' and B'.
- State the geometrical name for the figure ABA'B'.
- Find its perimeter.
Solution
a.
b. Co-ordinates of A' = (–6, –4)
Co-ordinates of B' = (0, –4)
c. ABA'B' is a parallelogram.
d. In ΔBA'B', BB' = 8 units, A'B' = 6 units
∴ BA' = `sqrt(6^2 + 8^2)`
= `sqrt(36 + 64)`
= `sqrt(100)`
= 10 units
`\implies` B'A = 10 units
AB = A'B' = 6 units
Perimeter of ABA'B'
= AB + BA' + A'B' + B'A
= 6 + 10 + 6 + 10
= 32 units
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