Answer:

Step-by-step explanation:
Density is the ratio of an object's mass to its volume, and it measures how compact an object is. The density of an object, p, is directly proportional to its mass, m, and inversely proportional to its volume, V:

First of all, keep in mind :
m --> cm = times by 100
cm --> mm = times by 10
mm --> cm = divide by 10
cm --> m = divide by 100
so we know that a square has 4 equal sides and to find the area of a square we do base*height. now these two numbers on the base and height are the same so we're basically squaring them to get the area of 81. therefore, we do the reverse so square root 81 and we get the answer 9cm
now let's convert 9cm to mm
= 9*10 = 90
area in mm = 90mm
now let's convert 9cm to meters
= 9/100=0.09
area in m = 0.09m
and finally, we already worked out the area in cm
= 9cm
hope this helped :)
Angle D = 47’
Angle B = 116’
32 + 32 = 64
180 - 64 = 116’
Angle E = 17’
116 + 47 = 163
180 - 163 = 17
Idk what to do after wards
18 Kids in his class you have to divide 72 by 4 which will give u 18
Good Luck! ~Sophie Hernandez