Answer:
x = 6 cm
Step-by-step explanation:
The area (A) of a triangle is calculated as
A = bh ( b is the base and h the height )
Here b = 12 and h = 4, then
A = × 12 × 4 = 6 × 4 = 24 cm²
Then area of parallelogram = 3 × 24 = 72 cm²
The area (A) of a parallelogram is calculated as
A = bh ( b is the width and h the height )
Here b = x and h = 12, thus
12x = 72 ( divide both sides by 12 )
x = 6
The width of the parallelogram is 6 cm