Do we need math in our life mostly people dont use it in the modern world only high tec jobs do

math is the foundation of everything. think about it you need to know how many dollar socks you can get, the amount of tip to leave, or even what your Christmas gifts will cost.

This is very helpful! Does this work for all triangles?

_Yes! it works for all triangles!_

why do you want to find area of a triangle

why...... why have a triangular room.....WHYYYYY

Lol, I'm 17 going to 12th grade next summer. Just reviewing the fundamentals of math. Hey kids make sure you guys focus and not taking anything for granted. It will help you once you get to higher level math, and keep you ahead of the comp. Keep Khanning!

Literally in the same situation. I went through geometry and algebra 1 but got by without studying and don't remember a thing, now Im going into 12th grade in 2 weeks. Khan Academy is saving my soul rn

the triangles are hard to do sometimes.

yea but youjust have to do it a ot

do you have to divide it by two

if you dont you are technically doing normal rectangle area

is there any other formula which can be used to find an area of a triangle

1) abc/4R (R is radius of circumscribed circle) 2) r/2×(a+b+c) (r is radius of inscribed circle) 3) If you know the coordinates of the three points, use the shoelace formula 1/2×|x₁y₂+x₂y₃+x₃y₁-x₂y₁-x₃y₂-x₁y₃|

Bro, I was in 4th grade last year (going to 5th this year and I am already in 6th grade math) and I am so ahead of my class but this video was helpful. You just have to pay attention to it and it will be super easy. I am a fast learner depending in what I am doing, it can be fun!! Just take my advice!

ya that what im doing. jump two grades ahead and your good you dont half to worry bout anything, my bro is skiping geometry at 7th grade(geomatry is 10 grade)he's going to do pre-calc next year let's hope he past's the skiping class!

Main content

6th grade

Course: 6th grade > Unit 8

Lesson 2: Areas of triangles

Area of triangles

Google Classroom

Intuition for why the area of a triangle is one half of base times height.

Intuition for why the area of a triangle is $A = \frac{1}{2} b h$ ‍

To see why the formula makes sense, drag the dot all the way to the right:

Whoa! You made a rectangle that's twice as big as the triangle! The area of the rectangle is

b h = 4 \times 5 = 20

square units, so the area of the triangle is

\frac{1}{2} b h = \frac{1}{2} \times 4 \times 5 = 10

square units.

Key intuition: A triangle is half as big as the rectangle that surrounds it, which is why the area of a triangle is one-half base times height.

Practice problem 1

What is the area of the triangle?
Drag the dot to help you remember the formula.

units

^{2}

Practice problem 2: right triangle

What is the area of the triangle?
Drag the dot to help you remember the formula.

units

^{2}

Practice problem 3: one vertex is hanging over the side

What is the area of the triangle?
Drag the dot to help you remember the formula.

units

^{2}

Want to join the conversation?

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Stephanie Pearce
Posted 6 years ago. Direct link to Stephanie Pearce's post “Do we need math in our li...”
Do we need math in our life mostly people dont use it in the modern world only high tec jobs do
Button navigates to signup pageComment on Stephanie Pearce's post “Do we need math in our li...”
(168 votes)
Answer
- Olivia Carpenter
  Posted 5 years ago. Direct link to Olivia Carpenter's post “math is the foundation of...”
  math is the foundation of everything. think about it you need to know how many dollar socks you can get, the amount of tip to leave, or even what your Christmas gifts will cost.
  Comment on Olivia Carpenter's post “math is the foundation of...”
  (120 votes)
maryannefalli
Posted 6 years ago. Direct link to maryannefalli's post “This is very helpful! Do...”
This is very helpful! Does this work for all triangles?
Button navigates to signup pageComment on maryannefalli's post “This is very helpful! Do...”
(108 votes)
Answer
- Klemmie
  Posted a year ago. Direct link to Klemmie's post “_Yes! it works for all tr...”
  Yes! it works for all triangles!
  Comment on Klemmie's post “_Yes! it works for all tr...”
  (36 votes)
LilD
Posted 6 years ago. Direct link to LilD's post “why do you want to find a...”
why do you want to find area of a triangle
Button navigates to signup pageComment on LilD's post “why do you want to find a...”
(39 votes)
Answer
- Harry Mary :]
  Posted 10 months ago. Direct link to Harry Mary :]'s post “why...... why have a tria...”
  why...... why have a triangular room.....WHYYYYY
  Comment on Harry Mary :]'s post “why...... why have a tria...”
  (16 votes)
Abdullah
Posted 5 months ago. Direct link to Abdullah's post “Lol, I'm 17 going to 12th...”
Lol, I'm 17 going to 12th grade next summer. Just reviewing the fundamentals of math. Hey kids make sure you guys focus and not taking anything for granted. It will help you once you get to higher level math, and keep you ahead of the comp. Keep Khanning!
Button navigates to signup pageComment on Abdullah's post “Lol, I'm 17 going to 12th...”
(35 votes)
Answer
- getboppedboi
  Posted 4 months ago. Direct link to getboppedboi's post “Literally in the same sit...”
  Literally in the same situation. I went through geometry and algebra 1 but got by without studying and don't remember a thing, now Im going into 12th grade in 2 weeks. Khan Academy is saving my soul rn
  Comment on getboppedboi's post “Literally in the same sit...”
  (14 votes)
myaphill1
Posted 5 years ago. Direct link to myaphill1's post “do you have to divide it ...”
do you have to divide it by two
Button navigates to signup pageComment on myaphill1's post “do you have to divide it ...”
(18 votes)
Answer
- Allixxison AKA Imposter !
  Posted 3 years ago. Direct link to Allixxison AKA Imposter !'s post “if you dont you are techn...”
  if you dont you are technically doing normal rectangle area
  Comment on Allixxison AKA Imposter !'s post “if you dont you are techn...”
  (13 votes)
Shannon Ritchie
Posted 5 years ago. Direct link to Shannon Ritchie's post “the triangles are hard to...”
the triangles are hard to do sometimes.
Button navigates to signup pageComment on Shannon Ritchie's post “the triangles are hard to...”
(20 votes)
Answer
- heilbel
  Posted a year ago. Direct link to heilbel's post “yea but youjust have to d...”
  yea but youjust have to do it a ot
  Comment on heilbel's post “yea but youjust have to d...”
  (2 votes)
ayse.sahingoz
Posted 4 years ago. Direct link to ayse.sahingoz's post “i feel like monkeys can s...”
i feel like monkeys can solve this but not me XD jk
Button navigates to signup pageComment on ayse.sahingoz's post “i feel like monkeys can s...”
(22 votes)
Answer
palwasha.asif
Posted 5 years ago. Direct link to palwasha.asif's post “is there any other formul...”
is there any other formula which can be used to find an area of a triangle
Button navigates to signup pageComment on palwasha.asif's post “is there any other formul...”
(18 votes)
Answer
- Elmion
  Posted 2 years ago. Direct link to Elmion's post “1) abc/4R (R is radius of...”
  1) abc/4R (R is radius of circumscribed circle)
  2) r/2×(a+b+c) (r is radius of inscribed circle)
  3) If you know the coordinates of the three points, use the shoelace formula
  1/2×|x₁y₂+x₂y₃+x₃y₁-x₂y₁-x₃y₂-x₁y₃|
  Comment on Elmion's post “1) abc/4R (R is radius of...”
  (10 votes)
Franklin
Posted 2 months ago. Direct link to Franklin's post “I don't really see how th...”
I don't really see how the putting the shape together can help me solve the problems on some of them. Other problems it works great.
Button navigates to signup pageComment on Franklin's post “I don't really see how th...”
(19 votes)
Answer
I AM LORD VOLDEMORT
Posted 6 months ago. Direct link to I AM LORD VOLDEMORT's post “Bro, I was in 4th grade l...”
Bro, I was in 4th grade last year (going to 5th this year and I am already in 6th grade math) and I am so ahead of my class but this video was helpful. You just have to pay attention to it and it will be super easy. I am a fast learner depending in what I am doing, it can be fun!! Just take my advice!
Button navigates to signup pageComment on I AM LORD VOLDEMORT's post “Bro, I was in 4th grade l...”
(14 votes)
Answer
- KEVIN
  Posted 6 months ago. Direct link to KEVIN's post “ya that what im doing. ju...”
  ya that what im doing. jump two grades ahead and your good you dont half to worry bout anything, my bro is skiping geometry at 7th grade(geomatry is 10 grade)he's going to do pre-calc next year
  let's hope he past's the skiping class!
  Button navigates to signup page
  (4 votes)

6th grade

Course: 6th grade > Unit 8

Intuition for why the area of a triangle is A=12bh‍

Practice problem 1

Practice problem 2: right triangle

Practice problem 3: one vertex is hanging over the side

Want to join the conversation?

Intuition for why the area of a triangle is $A = \frac{1}{2} b h$ ‍