A right triangle.
If it has no right angle then a scalene triangle would fit the given description
a rhombus, a quadrilateral without right angle, a quadrilateral with equal opposite parallel sides but no right angles
It is the right angle triangle which has 3 sides whereas all quadrilaterals have 4 sides.
A rectangle has four sides whereas a right angle triangle has only three sides.
A right triangle.
If it has no right angle then a scalene triangle would fit the given description
a rhombus, a quadrilateral without right angle, a quadrilateral with equal opposite parallel sides but no right angles
It is the right angle triangle which has 3 sides whereas all quadrilaterals have 4 sides.
It could be an isosceles right triangle, or it could be a non-regular specimen of any polygon with more than three sides.
If this makes sense.... something like this |\ | \ |___\ A three sided polygon that has one right (90 degree) angle and all three sides have different lengths
A rectangle has four sides whereas a right angle triangle has only three sides.
There are three sides.
Any polygon with more than three sides may have an angle greater than 180 degrees.
A right angle triangle
Five side is always a pentagon, but there's no pentagon that always has exactly one right angle. A regular pentagon has no right angles. An irregular pentagon can have one, two, or three right angles, or none.
Oh honey, that's a sassy little shape called a scalene triangle. It's got three sides of different lengths, two acute angles (less than 90 degrees), and one right angle (90 degrees). It's like the rebellious teenager of the triangle family.