Refer to the figure shown below.
When the point Y (-1,-3) is rotated 180 about O, it sweeps a semicircular arc to the point Y' (1,3).
The radius of the semicircle is
Answer: 3. Y' (1,3)
When the point Y (-1,-3) is rotated 180 about O, it sweeps a semicircular arc to the point Y' (1,3).
The radius of the semicircle is
Answer: 3. Y' (1,3)