Final answer:
To calculate the burner's area, divide the diameter by 2 to get the radius, then apply the area formula A = πr² with π approximated as 3.14. The area, when rounded to two significant figures, is 250 cm².
Step-by-step explanation:
The question asks us to calculate the area of a round electric burner given its diameter. The formula to find the area of a circle is expressed as A = πr², where A is the area, π (pi) is a constant approximately equal to 3.14, and r is the radius of the circle.
First, we must find the radius of the burner by dividing the diameter by 2. In this case, the diameter is 18 centimeters, so the radius r is 9 centimeters (18 cm / 2).
Then, we apply the area formula: A = πr² = 3.14 × 9 cm × 9 cm, which equals 3.14 × 81 cm² or 254.34 cm². Because the radius was given to two significant figures, the area should also be reported with two significant figures: A=250 cm².