# Circles test questions

### 1

What is a commonly used value of $$\pi$$?

### 2

Which of the following is not a formula to find the circumference of a circle?

### 3

What is the formula to find the area of a circle?

### 4

What is the circumference of a circle that has a diameter of $${7}~{cm}$$?

### 5

What is the circumference of a circle that has a radius of $${5}~{cm}$$?

### 6

What is the diameter of a circle that has a circumference of $${15}~{cm}$$?

### 7

What is the area of a circle that has a radius of $${5}~{cm}$$?

### 8

What is the area of a circle that has a diameter of $${16}~{cm}$$?

### 9

What is the area of a half circle that has a radius of $${10}~{cm}$$?

### 10

What is the radius of a circle that has an area of $${42}~{cm}^{2}$$?