A perfect circle — a circle without distortion or deformation, where every point is equidistant from the center.
このコインは長年使ったのに、真円に近い形を保っている。
Although this coin has been used for years, it has kept a nearly perfect circular shape.
図面には直径10cmの真円を描いてください。
Please draw a perfect circle with a 10 cm diameter on the drawing.
彼女はコンパスを使って真円を正確に描いた。
She used a compass to draw a perfect circle accurately.