Without cutting and reassembling, no more than the triangle that you started with. If you allow cutting and reassembling, then an infinite number of shapes.
A triangle
by 1 parallelogram and a triangle
triangle
A trapezoid and a triangle can make a triangle or another trapezoid, among others.
Any shape that is enclosed and has three sides is a triangle.
a pentagon
a BIG HUGE triangle i am in the 2ndgrade and i am 8 i am in glenarnden woods elem. in pgcps
triangle.
Octagon
a pentagon.
A cone or a bulged-out cone.
the shape is a heart.