Discusses the properties and types of triangles, explaining that a triangle is a closed figure with three sides and angles. It categorizes triangles into equilateral, isosceles, scalene, obtuse ...

An equilateral triangle fits into its outline three times in a full 360° turn. Image caption, ... An obtuse-angled triangle has one angle that is greater than 90°.

An equilateral triangle is a triangle where all sides are equal and where all angles are equal. Since we know that the angle sum of a triangle is 180 degrees, we know that in equilateral triangles ...