Why do they have to have a right angle?

It's just one of the 3 main angles in math. *Acute angles* are angles that are *less* than 90 degrees. *Right angles* are angles that are *exactly* 90 degrees. *Obtuse angles* are angles that are *more* than 90 degrees. You'll work with these three types of angles a lot more as you advance in math.

Is a quadrilateral just a shape that has four right angles?

No, a quadrilateral does not need to have 4 _right_ angles. It just needs 4 angles. Think of a trapezoid. This has 4 sides and 4 angles but the angles are not all right angles.

Is a trapezoid considered a quadrilateral?

Yes, it is a quadrilateral because it has four sides. And have a good day!

what is the difference between a rombus and a square?

A rhombus has 4 sides all of equal length but squares have all equal sides and all 90 degree angles

Concave, the opposite of convex, describes how a shape is curved. Concave means that a shape curves inward. E.g. in a shape with four (or more) sides, when one of the interior angles is over 180 degrees. You can think of a *star* - a star has 5 sharp angles that stick outwards AND 5 angle that point inwards. The ones pointing inwards indicate a concave shape. A function is concave when the second derivative is negative (<0)

I do not get that a petagon have 2 right angls.

Draw three sides of a square (the bottom line and the two side lines) Then put a peaked roof on it like the roof of a house. There you have five lines which is the definition of a pentagon (when you see the prefix PENT, that means 5) In this case, you will also see the two right angles where the bottom line and the two vertical lines meet. Get the idea?

How many things have right angles?

Millions of things. Animals can have right angle, cars, humans, and even food.

Do square has 4 right angles

yes it does have 4 right angles

Main content

Course: Get ready for 4th grade > Unit 6

Lesson 1: Quadrilaterals

Right angles in shapes (informal definition)

Q: How many things have right angles?

Millions of things. Animals can have right angle, cars, humans, and even food.

Q: Do square has 4 right angles

yes it does have 4 right angles

Google Classroom

Identify right angles in shapes.

Introduction

Many shapes have corners. We call a corner a right angle if we can fit a little square perfectly inside it.

Consider the trapezoid

Let's draw a square in each corner.

In which corners did the little square fit perfectly?

The trapezoid has two right angles.

Practice

First, let's study some more examples.

Now, try it yourself.

How many right angles are in this square?

How many right angles are in this pentagon?

Challenge problem

How many right angles does this shape have?

Want to join the conversation?

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sawyer.whitaker
Posted 6 years ago. Direct link to sawyer.whitaker's post “Is a diamond considered a...”
Is a diamond considered a quadrilateral?
Comment on sawyer.whitaker's post “Is a diamond considered a...”
(157 votes)
- Your Worst Nightmare
  Posted 5 years ago. Direct link to Your Worst Nightmare's post “Yes cause it still has 4 ...”
  Yes cause it still has 4 sides
  Comment on Your Worst Nightmare's post “Yes cause it still has 4 ...”
  (77 votes)
fuentesm1
Posted 3 years ago. Direct link to fuentesm1's post “Why do they have to have ...”
Why do they have to have a right angle?
Comment on fuentesm1's post “Why do they have to have ...”
(26 votes)
- Rachel
  Posted 3 years ago. Direct link to Rachel's post “It's just one of the 3 ma...”
  It's just one of the 3 main angles in math.
  Acute angles are angles that are less than 90 degrees.
  Right angles are angles that are exactly 90 degrees.
  Obtuse angles are angles that are more than 90 degrees.
  You'll work with these three types of angles a lot more as you advance in math.
  Comment on Rachel's post “It's just one of the 3 ma...”
  (36 votes)
aj319499
Posted 3 years ago. Direct link to aj319499's post “I do not get that a petag...”
I do not get that a petagon have 2 right angls.
(7 votes)
- Stephen White
  Posted 3 years ago. Direct link to Stephen White's post “Draw three sides of a squ...”
  Draw three sides of a square (the bottom line and the two side lines) Then put a peaked roof on it like the roof of a house.
  
  There you have five lines which is the definition of a pentagon (when you see the prefix PENT, that means 5) In this case, you will also see the two right angles where the bottom line and the two vertical lines meet.
  
  Get the idea?
  Comment on Stephen White's post “Draw three sides of a squ...”
  (18 votes)
piyush goyal
Posted 10 months ago. Direct link to piyush goyal's post “what is the difference be...”
what is the difference between a rombus and a square?
Comment on piyush goyal's post “what is the difference be...”
(8 votes)
- Sheen Handoo
  Posted 10 months ago. Direct link to Sheen Handoo's post “A rhombus has 4 sides all...”
  A rhombus has 4 sides all of equal length but squares have all equal sides and all 90 degree angles
  (12 votes)
matteo #1
Posted 4 years ago. Direct link to matteo #1's post “What is concave?”
What is concave?
Comment on matteo #1's post “What is concave?”
(8 votes)
- Timo
  Posted 4 years ago. Direct link to Timo's post “Concave, the opposite of ...”
  Concave, the opposite of convex, describes how a shape is curved. Concave means that a shape curves inward. E.g. in a shape with four (or more) sides, when one of the interior angles is over 180 degrees. You can think of a star - a star has 5 sharp angles that stick outwards AND 5 angle that point inwards. The ones pointing inwards indicate a concave shape.
  A function is concave when the second derivative is negative (<0)
  Comment on Timo's post “Concave, the opposite of ...”
  (12 votes)
LadybugBelleBossbaddie
Posted 3 years ago. Direct link to LadybugBelleBossbaddie's post “Is a quadrilateral just a...”
Is a quadrilateral just a shape that has four right angles?
(9 votes)
- Schuck
  Posted 3 years ago. Direct link to Schuck's post “No, a quadrilateral does ...”
  No, a quadrilateral does not need to have 4 right angles. It just needs 4 angles. Think of a trapezoid. This has 4 sides and 4 angles but the angles are not all right angles.
  (10 votes)
Jazariah(Zariah)
Posted 2 years ago. Direct link to Jazariah(Zariah)'s post “Is a trapezoid considered...”
Is a trapezoid considered a quadrilateral?
Comment on Jazariah(Zariah)'s post “Is a trapezoid considered...”
(9 votes)
- 24ocastronava
  Posted 2 years ago. Direct link to 24ocastronava's post “Yes, it is a quadrilatera...”
  Yes, it is a quadrilateral because it has four sides.
  And have a good day!
  Comment on 24ocastronava's post “Yes, it is a quadrilatera...”
  (9 votes)
annaehindbjorgen
Posted 3 months ago. Direct link to annaehindbjorgen's post “How many things have righ...”
How many things have right angles?
Button navigates to signup pageComment on annaehindbjorgen's post “How many things have righ...”
(6 votes)
Answer
- Myles
  Posted 3 months ago. Direct link to Myles's post “Millions of things. Anima...”
  Millions of things. Animals can have right angle, cars, humans, and even food.
  Comment on Myles's post “Millions of things. Anima...”
  (7 votes)
cheyenne0314@scaca
Posted 2 months ago. Direct link to cheyenne0314@scaca's post “Do square has 4 right ang...”
Do square has 4 right angles
Button navigates to signup pageComment on cheyenne0314@scaca's post “Do square has 4 right ang...”
(4 votes)
Answer
- akkem.2
  Posted 2 months ago. Direct link to akkem.2's post “yes it does have 4 right ...”
  yes it does have 4 right angles
  Comment on akkem.2's post “yes it does have 4 right ...”
  (7 votes)
HarperS
Posted 3 months ago. Direct link to HarperS's post “how many right angles can...”
how many right angles can a shape have?
Button navigates to signup pageComment on HarperS's post “how many right angles can...”
(4 votes)
Answer
- GrierR
  Posted 3 months ago. Direct link to GrierR's post “I think it is 4”
  I think it is 4
  Comment on GrierR's post “I think it is 4”
  (6 votes)