Yes, it can be split into two equilateral triangles,when we draw a diagonal
right triangles and
Yes! It's called a rhombus.
To create three different drawings showing a number of circles and triangles in which the ratio is 2:3 you can: Start with an equilateral triangle, draw a circle inside it, draw an equilateral triangle inside the circle, draw a circle in the triangle and then draw an equilateral tiangle in the smallest circle. Or, you could draw 3 triangles and 2 circles in a line. Or, you could draw 3 triangles on a line with 2 circles between them.
A quadrilateral, in general, is not a parallelogram. If it is a parallelogram then you will have some additional information about its sides and angles. If you do not have such information it is not possible to prove that it is a parallelogram. Draw a diagonal which will divide the quadrilateral into two triangles and use the additional information that you have to show that the triangles are congruent. This can then be used to show equality of sides or of angles: the latter can then be used to show that sides are parallel. Note that the choice of which diagonal may influence how (if at all) you proceed.
Well the most that i could do were 12.
you draw a square with equilateral triangles on each side.
A rectangle comes to mind. A rectangle is equiangular (all angles the same) and is also a quadrilateral (four-sided), but is not equilateral (all sides of the same length).