Question

5. Find the area of the triangle formed by the points
i) (1,2), (3,-4) and (-2,0)
ii) (9,-7), (2, 4) and (0,0)

Answer 1

Answer:

Step-by-step explanation:

Formula for area of triangle is  

∣

∣

∣

∣

∣

​  

 

2

1

​  

[x  

1

​  

(y  

2

​  

−y  

3

​  

)+x  

2

​  

(y  

3

​  

−y  

1

​  

)+x  

3

​  

(y  

1

​  

−y  

2

​  

)]  

∣

∣

∣

∣

∣

​  

 

where x  

1

​  

=1, y  

1

​  

=2, x  

2

​  

=2, y  

2

​  

=4, x  

3

​  

=3 and y  

3

​  

=1

Substitute the values, we get,

Area of triangle =  

∣

∣

∣

∣

∣

​  

 

2

1

​  

×[1(4−1)+2(1−2)+3(2−4)]  

∣

∣

∣

∣

∣

​  

 

=  

∣

∣

∣

∣

∣

​  

 

2

1

​  

×[3−2−6]  

∣

∣

∣

∣

∣

​  

 

=  

∣

∣

∣

∣

∣

​  

 

2

1

​  

×−5  

∣

∣

∣

∣

∣

​  

 

= ∣−5/2∣

Area always in absolute value.

So, area of the triangle =5/2 square units.

Answer 2

this is the answer !

hope you got it. this question is taken from the coordinate geometry chapter