1.) 8,281 people/km²
2.)
3.) 1226.88 grams
4.) 999.74 grams
5.) 6
I am not sure about number 2.
Answer:

Step-by-step explanation:
The distance between two points
is given by
.
Here
are the vertices of a triangle.

Longest side

Hence this is an acute triangle.
Answer:
$1,365
Step-by-step explanation:
Large Pizza: 40*12= $480
Medium Pizza: 57*10= $570
Small Pizza: 35*9= $315
480+570+315= $1,365