A seven sided shape is a heptagon.
Triangle
Icosolese Triangle
Ah, what a lovely question! The shape you're thinking of is a triangle. Triangles have three straight sides and no right angles. They come in all different sizes and can be found in nature and in art. Just imagine all the beautiful landscapes you could create with triangles!
That is a scalene triangle.
An equilateral triangle, has 3 equal sides and 3 equal angles. However, in a regular equilateral triangles, none of these angles are right angles (90 degrees), they are all 60 degrees.
A square with a rounded corner. =)
An irregular hexagon
If the question is about a plane shape with exactly 3 right angles it could be an irregular polygon of 5 or more sides. If the shape can have more than 3 right angles then a square or rectangle are also possible. Finally, in 3 or more dimensions, a polyhedron with any number of faces can have 3 or more right angles.
Any shape with more than 3 sides can have two pairs of equal sides and no right angles. If it only has 4 sides in total and isn't a parallelogram, then it's a trapezoid.
An equilateral triangle has 3 equal sides and 3 equal interior angles (of 60o.)
No polygon can have less than 3 angles. It would be a triangle with 3 sides but that has 3 angles.
Triangle
A triangle has 3 sides, 3 angles ( hence the name triangle ) and three kinds of common types ( Right, isosceles, and scalene. )
kite
A triangle.
Squares and rectangles always have, but anyshapewith more than 3 sides can have 2 right angles.
A Triangle