Question

find the value of k if the triangle formed by a(9, -10), b(7,-3) and c(0,k) is right angled at b​

fast!!!!!!!!!!

Answer 1

Step-by-step explanation:

slope of ab=-3+10/7-9=7/-2=-7/2

slope of bc=k+3/0-7=k+3/-7

if two lines are perpendicular then product of their slope is -1

-7/2*k+3/-7=-1

k+3/2=-1

k+3=-2

k=-5

using pythogorus theorem

ab^2+bc^2=ac^2

(7-9)^2+(-3+10)^2+(0-7)^2+(k+3)^2=(0-9)^2+(k+10)^2

4+49+49+(k+3)^2=81+(k+10)^2

102+k^2+6k+9=81+k^2+20k+100

6k+111=20k+181

-14k=70

k=-5