You can make any triangle, quadrilateral or pentagon with three suitable triangles.
Three triangles.
The shapes cosist of: two triangles and three rectangles.
triangles
Triangles can make various shapes depending on their sides and angles. Some common shapes formed by triangles include equilateral triangles (with three equal sides), isosceles triangles (with two equal sides), scalene triangles (with no equal sides), and right triangles (with one 90-degree angle).
Tow triangles and three rectangles.
Triangles
Impossible shapes. They are four sided shapes with three sides!
Triangles.
circle
Trapezoid.
triangles
Triangles have 3 sides.