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### Course: 4th grade>Unit 12

Lesson 1: Understanding angle measurement

# Measuring angles: FAQ

## What is an angle?

An angle is a way of measuring how much two lines, or "rays," are pointing away from each other. When two lines intersect (or cross), they create an angle. We can measure the size of that angle in degrees.
Try it yourself with these exercises:

## What's the difference between acute, right, and obtuse angles?

Acute angles measure less than ${90}^{\circ }$, right angles measure exactly ${90}^{\circ }$, and obtuse angles measure more than ${90}^{\circ }$.
Try it yourself with these exercises:

## What are benchmark angles?

Benchmark angles are common angles that we use to help us estimate the measure of other angles. For example, a right angle is a benchmark angle.
Try it yourself with this exercise:

## What does it mean to decompose an angle?

When we decompose an angle, we break it down into smaller angles that add up to the original angle.
Try it yourself with this exercise:

## Where do we use angles in the real world?

There are countless ways that angles are used in the real world!
Here are just a few examples:
• In construction, angles are essential for determining the correct shapes and dimensions of structures. For example, carpenters need to measure and cut angles to build frames for doors, windows, and roofs.
• In sports, athletes often use angles to their advantage. A basketball player, for example, will aim the ball at a certain angle to maximize their chances of making a shot. A baseball pitcher might throw a curveball by altering the angle of their wrist.
• When drawing or coloring, we might use angles to make sure the lines and shapes we're creating look the way we want them to.

## Want to join the conversation?

• Use a protractor to measure angles it will help you!
• and what is a protactor??
• Okay, I don't know who needs this but here. When you get to lesson 2 remember to put the dots in front of the number but on the line. You'll understand soon enough. Then for a recap 90 degrees is a right angle. anything less then 90 is acute, anything more is obtuse. 180 is half a circle and a full circle is 360. There are only three lessons in this unit i think. Good luck
• do you mean a full circle is 360 degrees
• This is so easy khan academy
• YES it is
• this is fun
• is a right angle always on the right?
• not always