<P> In several geometries , a triangle has three vertices and three sides , where three angles of a triangle are formed at each vertex by a pair of adjacent sides . In a Euclidean space , the sum of measures of these three angles of any triangle is invariably equal to the straight angle , also expressed as 180 ° , π radians , two right angles , or a half - turn . </P>
<P> In several geometries , a triangle has three vertices and three sides , where three angles of a triangle are formed at each vertex by a pair of adjacent sides . In a Euclidean space , the sum of measures of these three angles of any triangle is invariably equal to the straight angle , also expressed as 180 ° , π radians , two right angles , or a half - turn . </P>
sum of the interior angles of a triangle # 2
sum of the interior angles of a triangle # 2
180 °
180 °