Tipos de Ângulos: Reto, Agudo, Obtuso e Raso

🎯 What Will We Learn Today?

Not all angles are the same! Today we'll learn about the four main types of angles: right, acute, obtuse, and straight.

📚 The Four Types of Angles

Right Angle = 90° 📐

A right angle is exactly 90 degrees. It looks like the corner of a square or a perfect "L" shape. You'll see right angles everywhere — in books, doors, windows, and tables!

Acute Angle = Less than 90° 🔺

An acute angle is less than 90 degrees. "Acute" means "sharp" — these angles look pointy and narrow. Think of a pizza slice or the tip of a sharp pencil.

Obtuse Angle = Between 90° and 180° 🔽

An obtuse angle is between 90 and 180 degrees. It's wider than a right angle but not flat. Think of a reclining chair or an open laptop screen.

Straight Angle = 180° ➖

A straight angle is exactly 180 degrees. It looks like a straight line! Both arms form one continuous line going in opposite directions.

📊 Quick Reference

| Type | Degrees | Visual |
|------|---------|--------|
| Acute | Less than 90° | ∠ (narrow) |
| Right | Exactly 90° | ∟ (corner) |
| Obtuse | 90° to 180° | ∠ (wide) |
| Straight | Exactly 180° | — (flat line) |

🎮 Angle Hunt!

Activity: Walk around and find examples:

3 right angles (book corner, door frame, tile)

3 acute angles (scissors open slightly, a roof peak)

2 obtuse angles (lounge chair, laptop screen open)

1 straight angle (edge of a ruler)

💡 Memory Tricks

Acute sounds like "a cute" little angle — small and sharp!

Right angles are "just right" at 90°

Obtuse — think "obese" or big — it's a big, wide angle!

Straight is easy — it's just a straight line

📝 Practice Problems

What type of angle is 45°?

What type of angle is 120°?

What type of angle is exactly 90°?

What type of angle is 180°?

Draw one example of each angle type.

🎮 Play a Game!

Practice geometry skills with Orbit Integers — navigate through space while learning math!