A triangle
triangle
a pentagon.
Octagon
It make a line of symmentry and something else
triangleANS 2 - There is no 'best shape' - each bridge is designed for a particular place and can be almost any kind of construction.
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 pentagon.
Octagon
To make a strong bridge foundation, toothpick or steel, you should use a triangle based design.
It make a line of symmentry and something else
it makes shape like a triangle
triangle