Final answer:
To calculate the area 'a' with the given length (l=5) and width (w=4), use the formula a=lw and substitute the values to obtain a=5*4, which equals 20 square units.
Step-by-step explanation:
To find the value of a given the values for length (l) and width (w) using the formula a = lw, we simply substitute the given values into the equation. Here, l is 5 and w is 4, so the area a will be calculated as follows:
- First, write down the formula: a = lw.
- Next, substitute the given values for l and w into the formula: a = 5 * 4.
- Finally, perform the multiplication to find the area a: a = 20.
Therefore, the area a is 20 square units.