Answer:
X = 37.8
Explanation:
Since they stated angle BAC equals angle DEC, makes me believe these sides are just a factor of each other.
Because of that, we can make a proportion, then cross multiply and divide
Making that proportion, you get;
15. 18
---. =. ----
31.5. x
Cross multiply the (15)(x) = (31.5)(18), also known as
15x = 567
Last thing we do is divide both sides by 15 to get that X alone.
567/15 = 37.8
Concluding that x = 37.8