Answer:
C. 6.9
Step-by-step explanation:
Pretend this is a 2-d diagram and use the Pythagorean theorem.
Pythagorean theorem: a^2 + b^2 = c^2
a = 6 mm
b = 7/2 = 3.5 mm
c = x
6^2 + 3.5^2 = x^2
36 + 12.25 = x^2
48.25 = x^2
[tex]\sqrt{48.25} = \sqrt{x^2}[/tex]
x = 6.9
