some shapes

Equilateral Triangle	Equilateral triangles have all angles equal to 60° and all sides equal length. All equilateral triangles have 3 lines of symmetry.
Isoscles Triangle	Isosceles triangles have 2 angles equal and 2 sides of equal length. All isosceles triangles have a line of symmetry.
Scalene Triangle	Scalene triangles have no angles equal, and no sides of equal length.
Right Triangle	Right triangles (or right angled triangles) have one right angle (equal to 90° ).
Obtuse Triangle	Obtuse triangles have one obtuse angle (an angle greater than 90° ). The other two angles are acute (less than 90° ).
Acute Triangle	Acute triangles have all angles acute.

Is an Equilateral triangle a special case of an Isosceles triangle?

This means that there is some dispute as to whether an equilateral triangle is a special case of an isosceles triangle or not!

Most modern textbooks include use the 'at least' definition for isosceles triangles.

List of Geometric Shapes - Quadrilaterals

A quadrilateral is a polygon with 4 sides.

Quadrilaterals are also sometimes called quadrangles or tetragons.

There are quite a few members of the quadrilateral family. There are also some members which are a subset of other members of this family!
See below if this confuses you!

Square	Squares have 4 equal sides and 4 right angles. They have 4 lines of symmetry. All squares belong to the rectangle family. All squares belong to the rhombus family. All squares are also parallelograms.
Rectangle	Rectangles have 4 sides and 4 right angles. They all have 2 lines of symmetry (4 lines if they are also a square!) All rectangles belong to the parallelogram family.
Rhombus	Rhombuses (rhombii) have 4 equal sides. Both pairs of opposite sides are parallel. They all have 2 lines of symmetry (4 lines if they are a square!) All rhombuses belong to the parallelogram family.
Parallelogram	Parallelograms have 2 pairs of parallel sides. Some parallelograms have lines of symmetry (depending on whether they are also squares, rectangles or rhombuses), but most do not.
Trapezoid US (Trapezium UK)	Trapezoids US (Trapeziums UK) have one pair of parallel sides. Some trapezoids have a line of symmetry. Please note the differences between the definitions for US and UK.
Kite	Kites have 2 pairs of equal sides which are adjacent to each other.
Trapezium US (Trapezoid UK)	Trapeziums US (Trapezoids UK) are quadrilaterals with no parallel sides. Please note the differences between the definitions for US and UK.