Solve this :

1. Define concurrent lines.
2. In how many lines can two distinct planes intersect ?
3. If a point C lies between two points A and B such that AC = CB. Then Prove that AC = 1/2 AB
4. Prove that every line segment has one and only one mid-point.
5. In the figure, AC = BD, prove that AB = CD.
 

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Here is the link for the answer similar to your query:

https://www.meritnation.com/ask-answer/question/define-concurrent-lines/introduction-to-euclid-s-geometry/2966036

https://www.meritnation.com/ask-answer/question/where-does-the-two-planes-intersect/basic-geometrical-ideas/10496351

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