No products in the cart.

Find the area of triangle with …

CBSE, JEE, NEET, CUET

CBSE, JEE, NEET, CUET

Question Bank, Mock Tests, Exam Papers

NCERT Solutions, Sample Papers, Notes, Videos

Find the area of triangle with A(1,-4) and mid point of sides through being (2,-1)and (0,-1).
  • 1 answers

Sia ? 6 years, 6 months ago


Let E be the midpoint of AB.
{tex}\therefore \quad \frac { x + 1 } { 2 } = 2{/tex} or x = 3
and {tex}\frac { y + ( - 4 ) } { 2 } = - 1{/tex} or, y = 2
or, B(3, 2)
Let F be the mid-point of AC.Then,
{tex}0=\frac{x_1+1}{2}{/tex} or {tex}x_1=-1{/tex}
and   {tex}\frac { y _ { 1 } + ( - 4 ) } { 2 }{/tex} = -1 or, y1 = 2
or, C= (-1, 2)
Now the co-ordinates are A(1, - 4), B(3,2), C (-1,2)
Area of triangle
{tex}= \frac { 1 } { 2 } \left[ x _ { 1 } \left( y _ { 2 } - y _ { 3 } \right) + x _ { 2 } \left( y _ { 3 } - y _ { 1 } \right) + x _ { 3 } \left( y _ { 1 } - y _ { 2 } \right) \right]{/tex}
{tex}= \frac { 1 } { 2 } [ 1 ( 2 - 2 ) + 3 ( 2 + 4 ) - 1 ( - 4 - 2 ) ]{/tex}
{tex}= \frac { 1 } { 2 } [ 0 + 18 + 6 ]{/tex}
=  12 sq units.

https://examin8.com Test

Related Questions

X-y=5
  • 1 answers
(A + B )²
  • 1 answers
Prove that root 8 is an irration number
  • 2 answers
Find the nature of quadratic equation x^2 +x -5 =0
  • 0 answers
sin60° cos 30°+ cos60° sin 30°
  • 2 answers
Venu Gopal has twice
  • 0 answers

myCBSEguide App

myCBSEguide

Trusted by 1 Crore+ Students

Test Generator

Test Generator

Create papers online. It's FREE.

CUET Mock Tests

CUET Mock Tests

75,000+ questions to practice only on myCBSEguide app

Download myCBSEguide App