"A" right angle as in only one? A right-angled triangle.
If not only one:
Squares, rectangles, etc
If you mean an object in real life, then most chairs and tables will have legs set at right-angles to the floor/seat/tabletop if they're made right.
A pentagon.
a tiangled shaped desk.
Quadrilateral. No other special name. A kite could have 1 right angle - that's possible, but there is no special name for a quadrilateral with only 1 right angle.
An acute angle.
It could be a kite, a trapezium, a chevron or just an irregular quadrilateral with one right angle and no specific name.
It could be a kite, an arrowhead or an irregular quadrilateral with a right angle - which has no specific name.
From its right angle. right angle --> rect angle.
a right triangle
A right angle is a measure of 90 degrees or a 1/4 of a turn
If the angle is larger than a right angle it is obtuse
A 90o angle is a right angle, and a triangle with a right angle is called a right triangle.
90o angle