yes because the pressure or weight on the bridge pushes down and the weight goes down the two sides. the triangle is best when it is in the downward "V" shape.
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