The only triangle with the base being bisected perpendicularly is an isosceles triangle or an equilateral triangle. Therefore, [tex]KJ = KL[/tex]
[tex]KJ = 4x + 9\\KL = 11x - 61\\[/tex]
Since the sides are equal, we can equate the expressions to get the equation:
[tex]4x + 9 = 11x - 61\\11x - 4x = 70\\x = 10[/tex]
[tex]x[/tex] is equal to [tex]10[/tex].
Plug that in [tex]11x - 61[/tex] and you get [tex]110 - 61[/tex] which is [tex]49[/tex]. So, Option B is correct :D
