The sum of the three interior angles of a triangle is 180 degrees. In a regular triangle, each angle is equal and so each must be 180/3 = 60 degrees. Since 60 is less than 90 degrees, the angle cannot be obtuse.
No.
Irregular
No.
No because an equilateral triangle is a regular polygon whereas an obtuse triangle is irregular
No - not a plane triangle. The angles of a regular triangle must be equal. So an obtuse triangle, if regular, would have three obtuse angles. The sum of the angles would then be greater than 3*90 = 270 degrees. But the sum of angles of a triangle must be 180 degrees.
It is irregular
No because an obtuse angle is greater than 90 degrees and a regular triangle is an equilateral triangle that has 3 equal 60 degree angles that add up to 180 degrees.
An obtuse triangle has 3 sides.
obtuse triangle
An obtuse triangle has an obtuse angle.
An oxymoron. An equilateral triangle cannot be obtuse; an obtuse triangle cannot be equilateral.
obtuse triangle