The length and breadth of a rectangle are 4.5 mm and 5.9 mm. Keeping the number of significant figures in mind, its area in mm²

A27.00

B26.55

C26.6

D27

Answer:

Significant figures:

Significant figures in physics are the digits in a number that indicate the precision of a measurement and are the result of an actual measurement.

Every non – zero digits are significant figures.

e.g., 454.76 has 5 (five) significant figures.

All zeroes which lie between two non – zero digits are also significant figures.

e.g., 703.004 has 6 (six) significant figures.

All zeros after decimal but before a non – zero digit is not considered a significant figure.

e.g.,0.00465 has only 3 (three) significant figures.

A number is rounded to the needed number of significant digits by leaving one or more digits to the right.

Note:

The limiting term is the number with the least decimal places.
When adding / subtracting, the answer should have the same number of decimal places as the limiting term.
When multiplying / dividing, the answer should have the same number of significant figures as the limiting term.

Analysing the question,

Area of rectangle is length multiplied by breadth.
The area of this rectangle is 4.5×5.9 mm2 = 26.55 mm²
The number of significant figures will be the same as that in the limiting term.
Here the limiting term can be either the length or breadth, because both the terms have the same number of significant terms, that is 2.
The number of significant figures in the product, hence should also be 2.
Hence, 26.55 mm²when rounded should have 2 significant figures.
This can be written as 27 mm².

Note:

But the options 27. or 27.0 or 27.00, doesn't comes as the answer, as the number of significant figures will be

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