How will you check if a line is straight?

Question

without using the ruler...or any measuring instrument...

Answer 1

You must know 3 points on the line then find slope two points at a time. If the slopes are the same then it is a straight line.

Answer 2

Choose three points A, B, and C

If the distance from A to B plus the distance from B to C equals the distance from A to C showns below in equation form AB + BC = AC then Ac represents a straight line and the points are collinear. You did not say if this line was graphed on simply represented on a plane that was not gridded, so finding the distances could be done with a measurement tool or using the distance formula. Good luck.

Answer 3

If line drawn is on a paper or cardboard, place three all pins , one on each end of line and third one somewhere in middle. See through one end, if other two pins match with first one, it's a straight line otherwise not.
If line is drawn on any other hrd surface, simply check with edge of a book.

Answer 4

Use your one eye, if you can just see a point in a direction ,that can prove the line is straight.

Answer 5

Fold the paper along the line. The fold will be straight. Any deviations in the line will be clearly obvious.

Answer 6

if the points on the line satisfies the equation Y=mX+c then the line is a straight line.

Answer 7

1 way find area of triangle using 3 pts on it
area = 0

2nd way using 3 pts on it find slope of any 2 pairs
slopes are equal

3rd way using 3 pts . find eqt of line using 2 pts
if 3rd pt satisfies eqt => straight line

Answer 8

take a thread with small pebbel at one end.....and other endto a nail on the walll........now wait till it stop oscilation....then put the paper on which line is present at the background of thread and see whether it is straight or not?

Answer 9

if your at a new desk put the line on the edge of the desk and bada bing bada boom

Answer 10

Use your book edge