Answer:
570 ft²
Explanation:
Basically, you find the area of Juan and Matthew's gardens then add them up.
First let's find the area of Juan's garden.
Area is equal to length times width (
)
So you do 16 * 12 which equals 192.
Now let's find the area of Matthew's garden.
So you do 18 * 21 which equals 378.
Then you add up both areas.
192 + 378 = 570