Do you also use the verb encircle here? You can say coins are a circle in shape, the shape of coins is a circle, coins are circular (in shape). 知乎，中文互联网高质量的问答社区和创作者聚集的原创内容平台，于 2011 年 1 月正式上线，以「让人们更好的分享知识、经验和见解，找到自己的解答」为品牌使命。知乎凭借认真、专业.
Circle K
Of course, the simple phrase circles are round that you mentioned. When talking about children's textbooks, they are sometimes asked to circle the correct answer.
