Answer:
option A : 25
Step-by-step explanation:
Given :
P = (- 6, 7) , Q = ( 2 , 1 ) , R = ( -1 , -3)
Find the length of PQ ,QR , PR.
Using distance formula to find the lengths.
[tex]distance = \sqrt{(x_2 - x_1 )^2 + (y_ 2- y_1)^2[/tex]
[tex]PQ = \sqrt{(2 -- 6)^2 + (1-7)^2} = \sqrt{8^2 + 6^2 } = \sqrt{64 + 36 } =\sqrt{100} = 10\\\\QR = \sqrt{(2 --1)^2 + (-3-1)^2}= \sqrt{3^2 + 4^2} =\sqrt{9+ 16} =\sqrt{25} = 5\\\\PR = \sqrt{(-1--6)^2 + (-3 -7)^2} = \sqrt{5^2 + 10^2} = \sqrt{25 + 100} = \sqrt{125}[/tex]
Clearly , the triangle satisfies Pythagoras theorem :
Square of larger side = Sum of squares of other sides.
Therefore , PQR is a right triangle,
with base = 5, height 10 and slant height(hypotenuse) = [tex]\sqrt{125}[/tex] .
[tex]Area = \frac{1}{2} \times base \times height[/tex]
[tex]=\frac{1}{2} \times 5\times 10\\\\= 5 \times 5 \\\\= 25 \ square\ units[/tex]
