either a right angle or a acute angle it depends what way you turn the triangle
One angle (corner) must to 90 degrees.
They are:equilateralacute angled isoscelesacute angle scaleneright angled isoscelesright angle scaleneobtuse angled isoscelesobtuse angle scalene.
The right-angled triangle.
An obtuse angled triangle.An obtuse angled triangle.An obtuse angled triangle.An obtuse angled triangle.
A right angle triangle
Because the Bottom left corner makes a 90 degree angle like this |_ and a 90 degree angle is called a Right angle thus the name Right angled Triangle
One angle (corner) must to 90 degrees.
They are:equilateralacute angled isoscelesacute angle scaleneright angled isoscelesright angle scaleneobtuse angled isoscelesobtuse angle scalene.
It will have an L shape flipped around at the corner. or you can use a protractor or type in google images 'right angle triangle' they will have an L shape at the corner of the right angled triangle.
It is an obtuse angled triangle.
The right-angled triangle.
An obtuse angled triangle.An obtuse angled triangle.An obtuse angled triangle.An obtuse angled triangle.
A right angle triangle
A right(-angled) triangle
Right angled triangle.
A scalene triangle, an equilateral triangle, an isosceles triangle and a right-angle triangle, acute-angled triangle, obtuse-angled triangle
An obtuse angled triangle.