Hey there! I'm happy to help!
First, let's find the radius. The radius is half of the diameter.
8.4/2=4.2
Here's how to find the area of a circle.
Square the radius.
4.2²=17.64
And multiply by pi (3.14 in our case)
17.64(3.14)=55.3896
We round to the nearest tenth, giving us an area of 55.4 ft²
Have a wonderful day! :D
