Draw a square. Tracing a pad of Post-It notes works like a charm if your freehand lines are a little shaky. Label the side length *s* (or *x*, or *y*, or @, or whatever variable you like). We can see that the area *A* of the square is given by the formula *A* = *s*^{2}.
Because *A* is 100, we find the answers if we solve the formula. 100 = *s*^{2} *s* = ± 10
However, the answer -10 doesn't make any sense in the context of this problem. What are negative centimeters? The metric system may seem a little weird to many of us, but it's not *that* weird. A good way to show work here would be to write something like this sentence: "Since the length of a side can't be negative, we can eliminate the answer *s* = -10. The final answer is *s* = 10 cm." Then sit back, cross your arms, and wait for the extra credit and accolades to come rolling in. |