# Lesson 5Circular ReasoningPractice Understanding

Determine the angles of rotational symmetry and the number of lines of reflective symmetry for each of the polygons below.

### 1.

Equilateral Triangle

Rectangle

Rhombus

Regular Hexagon

Square

### 6.

Regular Decagon

Solve each right triangle by finding the missing angles and sides.

## Set

Use the figure for problems 11–13.

### 11.

Given: and are both .

Find .

Find .

Find .

Find .

### 12.

has two sides that are radii of the circle.

#### a.

What type of triangle is ?

#### b.

Identify another triangle formed by two radii.

### 13.

Given: .

Find .

Find .

Find .

Find .

#### e.

Find .

Use the figure for problems 14–16.

### 14.

Identify the right angles in . How do you know?

### 15.

Identify four inscribed angles with the same measure. How do you know?

Given:

Find .

Find .

Find .

Find .

Find .

## Go

Find the indicated distances and areas.

### 17.

is cut by two diameters that are perpendicular to each other.

#### a.

Find the distance to walk along arc .

#### b.

Find the area inside one of the four sectors.

#### c.

Find the distance to walk along the following path: Start at point and go to then to and over to then back to .

### 18.

is cut by three diameters that create equal angles at the center of the circle.

#### a.

Find the distance to walk along arc .

#### b.

Find the area inside one of the six sectors.

#### c.

Find the distance to walk along the following path: Start at point go to then to then to followed by and then back to .