Which of the following represent the length of a diagonal of this trapezoid?
A
B
C
D

Answer:
[tex]\sqrt{\left(a+b\right)^{2}+c^{2}}[/tex]
Step-by-step explanation:
The distance between the line joining points A (-b, c) and C (a, o) will be the length of the diagonal of given trapezoid.
Now, [tex]x_{1} = - b,\ y_{1} = c\ and\ x_{2} = a, y_{2} = 0[/tex]
Now, using distance formula,
AC = [tex]\sqrt{\left (x_{2}-x_{1}\right )^{2}+\left (y_{2}-y_{1}\right )^{2}}[/tex]
AC = [tex]\sqrt{\left(a-(-b) \right)^{2}+\left(0-c\right)^{2}}[/tex]
AC = [tex]\sqrt{\left(a+b\right)^{2}+\left(-c\right)^{2}}[/tex]
AC = [tex]\sqrt{\left(a+b\right)^{2}+c^{2}}[/tex]
Therefore, the length of diagonal AC of trapezoid = [tex]\sqrt{\left(a+b\right)^{2}+c^{2}}[/tex]
So, option (4) is the right option.