Hello there!
We see 3 pointed dots on the line demonstrated.
For [tex] BD=18 [/tex]
And [tex] DC=18 [/tex] mainly because both [tex] BD [/tex] and [tex] DC [/tex] have the same length. Therefore, as we can see, [tex] BC [/tex] would be crossing [tex] C [/tex]. Therefore, we would just add 18+18, or multiply 18 by 2.
Your answer: 36
