The answer is D. 12 cm, because in order to find the area of a parallelogram you need the formula A = (b)(h), which is base times height. So 20cm x 12cm equals 240cm^2 :)
To multiply three factors, we first multiply two of the factors together. Then we multiply the product we get by the third factor. Since multiplication is commutative, we may multiply numbers in any order.
