quadralateral...draw thang with 4 sides made from strate lines
Diagonal=line tween 2 korners kros from eech other
Yu get a triangel
If yuno leng or sides av the quad thang, yu hav length av 2 sides av triangel
But yu need 1 other thang tu figger out triangel...sumthun yu yuze tu
get angel tween the 2 sides