zhè gè / sān jiǎo xíng / de / sān gè / jiǎo / zhōng / yǒu / yī gè / shì / zhí jiǎo / suǒ yǐ / tā / shì / zhí jiǎo sān jiǎo xíng

这个三角形的三个角中有一个是直角，所以它是直角三角形。

This triangle has a right angle among its three angles, so it is a right-angled triangle.