Hey there :)
We know that the area of a parallelogram
Area = base × height
We are given:
Base = 18 units
Height = 10 units
Apply the formula
A = 18 × 10
= 180 units²
and then
Area = 12 × h
180 = 12h
Divide by 12 on either side to isolate h and find its value
[tex] \frac{180}{12} = \frac{12h}{12} [/tex]
h = 15 units