Given
base=2x+6
height=x+4
and
area=56 square units
56=1/2 times (2x+6) times (x+4)
times bot sides by 2
112=(2x+6)(x+4)
expand
112=2x²+14x+24
divide both sides by 2
56=x²+7x+12
minus 56 both sides
0=x²+7x-44
factor
waht 2 numbers mulitply to get -44 and add to get 7
11 and -4
0=(x-4)(x+11)
set to 0
x-4=0
x=4
x+11=0
x=-11
false, measures can't be negative
x=4
height=x+4
height=4+4=8
base=2x+6
base=2(4)+6=8+6=14
x=4 and base=14 and height=8
because there are 12 in one layer and there are 3 layers
