Yes
no
No. An isosceles trapezium (isosceles triangle with its apex removed) would have congruent diagonals but it is not a parallelogram.
Yes. Any triangle will tessellate.
It depends. Strictly speaking, a semi-regular tessellation uses two (or more) regular polygons and, since neither an isosceles triangle nor a parallelogram is regular, it cannot be a semi-regular tessellation. However, a less strict definition allows non-regular components.
isosceles triangle
Yes under certain dimensional conditions.
no
no
No - a triangle by definition has 3 sides. A parallelogram has 4.
There is no such thing as a regular isosceles triangle. The only regular triangle is an equilateral triangle. Having said that, any triangle will produce regular tessellation.
isosceles triangle
They both have 3 sides.Both have at least 2 equal sides.They both have acute angles.Both are triangles.Both can tessellate.
No. An isosceles trapezium (isosceles triangle with its apex removed) would have congruent diagonals but it is not a parallelogram.
Yes.
Yes
Yes. Any triangle will tessellate.
Yes, any type of triangle or quadrilateral will tessellate.