FTCE General Knowledge Math Practice Test

Which formula calculates the area of a circle?

1. 1/2 h(a + b)

2. (3.14)r^2

3. 1/3Bh

4. 1/2PI

The correct answer is: (3.14)r^2

The formula to calculate the area of a circle is indeed represented by \( \pi r^2 \), and in the context of your answer, \( (3.14)r^2 \) serves as a practical approximation of \( \pi \). This formula expresses the area in terms of the radius \( r \) of the circle, indicating that the area is proportional to the square of the radius. The numerical approximation of \( \pi \) as 3.14 simplifies calculations and demonstrates how the radius contributes to the area. Other options relate to different geometric calculations: one is for the area of a trapezoid, another for the volume of a prism, and the last option does not represent a standard geometric formula for area. Hence, the focus on radius squared multiplied by \( \pi \) directly leads to the correct understanding of how to measure the area of a circular shape.