20.7123152 thats the answer i looked it up
The internal angle sum of a quadrilateral is :
C. 360°
The sum of internal angles of a polygon is determined by a formula :

where n represents number of sides.
In a quadrilateral there are four sides,
So, plugging 4 in the formula :
_____________________________

Well first you take 78 and turn it to 7.8
then multiply by 10000
therefore 7.8*10000= ?
Do rise over run and you should end up with 4 and 3 hope that help