That's an "equilateral triangle". Each inside angle is 60 degrees.
A shape with opposite sides parallel and of the same length and four right angles is a rectangle.
A shape with 3 sides is exactly triangular as for example an equilateral triangle has 3 equal sides and 3 equal angles of 60 degrees that add up to 180 degrees.
A rectangle has 4 sides not the same length and 4 right angles.
A hexagon has all six sides in equal length and all angles in equal measure.
Its a diamond :]
A rhombus
a rhombus
A rhombus.
A square
Any regular shaped polygon has equal angles and equal sides
parrallelogram
rectangle