late 14c., from Old French triangle (13c.), from Latin triangulum "triangle," noun use of neuter of adjective triangulus "three-cornered, having three angles," from tri- "three" (see tri-) + angulus "corner, angle" (see angle (n.)).
实用例句
1. The sum of all the angles of a triangle is 180 degrees.
三角形内角总和为180度。
来自柯林斯例句
2. The hypotenuse is the longest side of a right triangle.
直角三角形的斜边是直角三角形中最长的边.
来自《简明英汉词典》
3. The base angles of an isosceles triangle are equal.
