Why are arch bridges stronger than beam ones?

[jadoreparis30]

When building a pasta bridge, why are arches or triangular peaks able to support more weight than flat beam bridges? Assume the weight would be attached to the base/deck of the bridge.

I'm building a pasta bridge for my Physics class and I was curious. Thank you!

 

[Dale]

Is pasta stonger in compression or tension?

Also, is there more pasta in an arch/peak or a flat beam?

 

[jadoreparis30]

I believe pasta would be stronger in tension, but weak in compression.

 

[Dale]

Oh, one more thing to think about: if you take a flat noodle (e.g. linguini) is it stronger with "edge" vertical or the "flat"?

PS, I am not 100% sure about pasta, but most brittle materials are weak in tension and strong in compression