A box of some sort, or a door
a right angle is a right angle
an angle with a acute and right angle
A right angle triangle.
right-angle triangle has at least one right angle .
A right-angle is one of 90 degrees.
A trapezoid can be drawn with one right 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.
a right triangle has one right angleA triangle with a right angle is a right triangle.
A right angle is one of 90 degrees. An acute angle of 30 degrees would be one third of that.
What is one quarter of a right angle turn?"
A triangle with one angle measuring 90˚ is a right triangleIt's a right triangle because the 90˚ angle is a right angle