Final answer:
To calculate the perimeter of a rectangle, apply the formula P = 2l + 2w, where l is the length and w is the width. If the width is measured as 1.25 cm, the perimeter calculation would require the length dimension and involve units of centimeters. Rulers are essential for obtaining these measurements, taking into account significant figures for precision.
Step-by-step explanation:
To find the perimeter of a rectangle, you use the formula P = 2l + 2w, where l is the length and w is the width. Based on the provided measurements, the perimeter of the rectangle would be 2(1.25 cm) + 2(w cm), where w cm is the other dimension that has not been specified. For a square with side length a, the perimeter is simply 4a. Remember that the unit of measurement for the perimeter will be the same as that for the sides, so in this case, it's in centimeters.
To accurately measure an object's width, use a ruler as described. In the given scenario, the rectangle's width has been measured to be 1.25 cm with three significant figures. If you're given the dimensions of a rectangle, like the town square with a length of 39.2 meters and a width of 17.5 meters, you'd use the formula provided, P=2l+2w, to find the perimeter, which would be 2(39.2 m) + 2(17.5 m). This example emphasizes understanding units and significant figures when dealing with measurements in geometry.