三さん面めん鏡きょう

noun

three-sided mirror; three-way mirror

A mirror with three panels, often used for seeing oneself from multiple angles, such as in fitting rooms or on a vanity.

• 試し着ちゃく室しつに三さん面めん鏡きょうがあると、後うしろ姿すがたも確かく認にんできて便べん利りだ。

  Having a three-way mirror in the fitting room is convenient because you can check your back view as well.