# 8.05 Estimate angles

Lesson

## Ideas

Being able to  identify and compare angle  can help us in this lesson. Let's try this problem to review.

### Examples

#### Example 1

Which of these angles is larger?

A
B
Worked Solution
Create a strategy

Choose the option with a larger turn between the lines.

Apply the idea

Idea summary

Angles can be compared by how large the turn is between the lines.

## Estimate angles

Let's see how we can use angles we know to estimate other angles.

### Examples

#### Example 2

Which angle is equal to 45 degrees?

A
B
C
Worked Solution
Create a strategy

Recall that a 45\degree angle is half of a 90\degree angle, or right angle:

Apply the idea

Option A is larger than a right angle. Option B looks smaller than half a right angle. Option C looks like half a right angle.

So the answer is option C.

Idea summary

If we remember some important angles, we can use those to estimate other angles.

### Outcomes

#### MA3-16MG

measures and constructs angles, and applies angle relationships to find unknown angles