Question

what is the value of π (pi) approximated to two decimal places?
a. 3.12
b. 3.14
what is the formula for the circumference of a circle with radius r?
a. $c = 2pi r$
b. $c = pi r^2$
which of the following is true about π?
a. it is an irrational number
b. it is exactly 3
what is the circumference of a circle with a diameter of 14 meters?
a. 28 meters
b. 43.96 meters

Explanation:

First Question: What is the value of π (pi) approximated to two decimal places?

The value of π is approximately 3.14159..., so when rounded to two decimal places, it is 3.14. Option a (3.12) is incorrect.

The formula for the circumference \( C \) of a circle is \( C = 2\pi r \) (where \( 2r \) is the diameter \( d \), so \( C=\pi d \) is also equivalent). The formula \( C = \pi r^2 \) is for the area of a circle, so option b is incorrect.

\( \pi \) is an irrational number, meaning it cannot be expressed as a fraction of two integers and its decimal expansion is non - repeating and non - terminating. It is not exactly 3 (3 is just a very rough approximation), so option b is incorrect.

Answer:

b. 3.14

Second Question: What is the formula for the circumference of a circle with radius \( r \)?