Hello!
We have the following data:
if: 1 ft = 12 in
So:
x: 13 '' = 13 * (12 '') + 3 '' = 156 '' + 3 '' = 159 '' (inches)
y: 11 ft 5 in = 11'5 "= 11 * (12") + 5 "= 132" + 5 "= 137" (inches)
Now, let's calculate the Area, let's see:
A = x * y
A = 159 * 137
A = 21783 in²
Let's transform square inches into square feet, we have:
1 in² ------------------- 0.00694 ft²
21783 in² ------------ A
A = 21783 * 0.00694
A ≈ 151.17 ft² ← (answer)
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I Hope this helps, greetings ... DexteR! =)