The square root of 18 can be approximated by comparing it to two nearby perfect squares that are less than 18 and greater than 18.
≈ 4 m
Practice makes perfect
We are asked to approximate the side length of a mural with an area of 18m^2 to the nearest whole number. First, let's recall that the area of a square can be found by squaring the side length s.
A=s^2
By substituting the area into the formula, we can find the side length. Notice that a length cannot be negative, so we will only consider positive solutions.
Since 18 is not a perfect square, and we are not asked for an exact answer, we can find an approximation by comparing 18 to the nearest perfect squares. We will use perfect squares less than and greater than 18. Let's try 16 and 25.
Now we know that the side length must be some number between 4 and 5. To decide which value is our answer we need to think about the relationship between 16, 18, and 25.
16<1_28<25_7
The difference between 16 and 18 is 2, while the difference between 18 and 25 is 7. Therefore, 18 is closer to 16 and, subsequently, sqrt(18) is closer to sqrt(16). We conclude that the side length of the mural is approximately 4 m.
