Question

find the area of triangle if their vertices atmre a(5, 12) b(5,0) c(0,0)

Answer 1

area would be 30....if u draw triangle, u will see a right angle triangle will be formed

Answer 2

vertices are a(5,12) , b(5,0) & c(0,0)

so $x_{1}=5 , x_{2}= 5 , x_{3}=0 and y_{1}=12 , y_{2}=0 , y_{3}=0$

ar. of triangle= $1/2[x_{1}(y_{2}-y_{3})+x_{2}(y_{3}-y_{1})+x_{3}(y_{1}-y_{2})$

                      = 1/2 [5(0-0)+5(0-12)+0(12-0)]

                      = 1/2 [5(0)+5(-12)+0(12)]

                      = 1/2 [0-60+0]

                      = 1/2 [-60]

                      = -30

∴ ar. of triangle abc= -30  

but any area of any shape does not exist in -ve

so may be it is not a triangle or check my calculation

i hope it will help you