Segment DE is midsegment of triangle ABC. What is the length of segment DE?
A) 5
B) 10
C) 15
D) 20

Answer:
B) 10
Step-by-step explanation:
If DE is midsegment of the triangle, we know that AC measures twice as DE.
In the problem we have that AC = x + 15 and DE = x + 5
Writing this as an equation we have:
[tex]x + 15 = 2(x+5)\\x+15=2x +10\\15-10=2x-x\\5=x[/tex]
Therefore x = 5 and the length of segment DE is:
x + 5 = 5 + 5 = 10
Therefore the correct answer is B) 10