A square 3

A square (with side b=2ft) is removed from the right-hand corner of a square board with side a= 12 ft. What is the area of the remaining board in square feet?

Correct answer:

S =  140 ft²

Step-by-step explanation:

$$\begin{gathered} a=12\text{ft} \\ b=2\text{ft} \\ {S}_1=a^2=12^2=144{\text{ft}}^2 \\ {S}_2=b^2=2^2=4{\text{ft}}^2 \\ S=S_1-S_2=144-4=140{\text{ft}}^2 \end{gathered}$$

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