60 degrees: acute
Each interior angle of a regular is 108 degrees which is an obtuse angle and each exterior angle is 72 degrees which is an acute angle
A right-angle triangle.
If one angle is a right angle, it is a right triangle. If one angle is an obtuse angle, it is an obtuse triangle. If there are no right nor obtuse angle then it is an acute triangle.
right angle triangle
45 degrees is an angle, not a triangle.A triangle containing an angle of 45 degrees can be any kind of triangle except an equilateral triangle.
A right triangle is a triangle with a right angle.a right triangle is a triangle with 1 side as a right angle
A regular pentagon (5 sides)
an equaladderal triangle
An obtuse triangle.
A right triangle has a right angle (thus called a right triangle), 90 degrees
That would be a right triangle. Any triangle that has a right angle in it is a right triangle.