Focus on triangles DFC and DFE:
- They are both right triangles because DF is perpendicular to EC
- DC=DE
- DF is a common side
So, the two triangles are congruent. It follows that CF=FE, and in particular

And since x=3, the length of EF is

Answer: c
Step-by-step explanation:
Answer:
b and d
Step-by-step explanation:
parallel means go in the exact same direction and if they never ended, they would never touch
The quotient if the equation is x3