Question

If the area of triangle whose vertices are p( -2 ,0 ) , Q ( 3,0) , R ( 0 , k ) is 9 unit then find the value of k​

Answer 1

Answer:

We know that , area of a triangle with vertices (a  

1

​

,y  

1

​

),(x  

2

​

,y  

2

​

) and (x  

3

​

,y  

3

​

) is given by  

Δ=  

2

1

​

 

∣

∣

∣

∣

∣

∣

∣

∣

​

 

x  

1

​

 

x  

2

​

 

x  

3

​

 

​

 

y  

1

​

 

y  

2

​

 

y  

3

​

 

​

 

1

1

1

​

 

∣

∣

∣

∣

∣

∣

∣

∣

​

 

∴Δ=  

2

1

​

 

∣

∣

∣

∣

∣

∣

∣

∣

​

 

−3

3

0

​

 

0

0

k

​

 

1

1

1

​

 

∣

∣

∣

∣

∣

∣

∣

∣

​

 

Expanding along R  

1

​

 

9=  

2

1

​

[−3(−k)−0+1(3k)]

⇒18=3k+3k=6k

∴K=  

6

18

​

=3

Step-by-step explanation: