Question

Triangle ABC has the following vertices:

A(7,-2)
B(-1,-8)
C(5,0)
Is triangle ABC an isosceles triangle, and why?

Answer 1

Calculate the lengths of the 3 sides of the triangle:

AB =

`\sqrt{(7 - ( - 1)) ^(2) + (( - 2) - ( - 8))^(2) } = 10`

BC =

`\sqrt{(( - 1) - 5) ^(2) + (( - 8) - 0)^(2) } = 10`

AC =

`\sqrt{(7 - 5) ^(2) + (( - 2) - 0)^(2) } = 2 √(2)`

Because AB = BC

=> ️ABC is an isoscelea triangle at B