Final answer:
The area of the first circle with radius 11.2 cm is 394.10 cm², and the area of the second circle with radius 9 m is 254.50 m², both calculated using π as 3.142 and given to two decimal places.
Step-by-step explanation:
To work out the area of the two circles presented in the student's question, the formula A = πr² is used, which is the standard equation for the area of a circle with radius r. Taking π as 3.142, we can calculate the respective areas by inserting the given radius values.
Circle with radius 11.2 cm
A = 3.142 × (11.2 cm)²
A = 3.142 × 125.44 cm²
A = 394.09728 cm²
Since the radius was given to two decimal places, we'll also express the area to two decimal places:
A = 394.10 cm²
Circle with radius 9 m
A = 3.142 × (9 m)²
A = 3.142 × 81 m²
A = 254.502 m²
Expressing the area to two decimal places:
A = 254.50 m²