Given
∆PQR points are P(-2,5), Q(-1,1), and R(7,3)
Determine whether ∆PQR is a right triangle
To proof
As given ∆PQR points are P(-2,5), Q(-1,1), and R(7,3)
First find out the sides of triangle
FORMULA
Distance formula between two points
![D^(2)= (x_(2)-x_(1))^(2)+(y_(2)-y_(1))^(2)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/p1yhdk1ydxtexoi64wdl015602gl965nju.png)
Distance between two points P(-2,5) and Q(-1,1)
![PR = \sqrt{(-1+2)^(2)+(1-5)^(2) }](https://img.qammunity.org/2019/formulas/mathematics/middle-school/aqnisbh2p32qnnu3z05091s9yp3tulr0af.png)
Distance between two points Q(-1,1)and R(7,3)
![QR = \sqrt{(7+1)^(2) +(3-1)^(2) }](https://img.qammunity.org/2019/formulas/mathematics/middle-school/8mgftuo2984ayb4nw9hof2ucr3gpf066w0.png)
![QR =√(68)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/luehks3299e6bz28da3gcsgrhdlz63n2zf.png)
Distance between two points R(7,3) and P(-2,5)
![RP =\sqrt{(-2-7)^(2) + (5-3)^(2) }](https://img.qammunity.org/2019/formulas/mathematics/middle-school/9wju69jq6l3u8rdq51f9v25wbdk46rloon.png)
![RP=√(85)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/j9mwhf4gewe8qlkoor06qrxdsm8nespi9j.png)
now show that ∆PQR is a right triangle
![RP^(2) = PQ^(2) +QR^(2)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/93y6f9kro8n04ibwdd0o2hf1nacs0eytbm.png)
Putting the value given above
![(√(85)) ^(2) = √(17) ^(2) +√(68) ^(2)](https://img.qammunity.org/2019/formulas/mathematics/middle-school/a3q2337t0t0qasjq1pnxbpdqbg4bqqpcak.png)
85 = 17 +68
85 =85
In the right triangle
HYPOTENUSE² = BASE² + PERPENDICULAR²
This is prove above
Hence ∆PQR is a right triangle
Hence proved