ChatterBank2 mins ago
Maths Question
6 Answers
ABCD is a parallelogram. A, B and C have coordinates (2,3) , (4,7) and (8,11). Find the equation of DC
Answers
You should plot the three known points on graph paper and it will become obvious where the fourth point of a parallelogra m should be.
Knowing the 2 points D & C;
The line through two distinct points (x1, y1) and (x2, y2) is given by
y = y1 + [(y2 - y1) / (x2 - x1)]·(x - x1)
Knowing the 2 points D & C;
The line through two distinct points (x1, y1) and (x2, y2) is given by
y = y1 + [(y2 - y1) / (x2 - x1)]·(x - x1)
17:58 Mon 24th Oct 2011
DC is parallel to AB - it's a parallelogram as it's parallel it will have the same gradient as AB you can work out the gradient by the difference in the y cor-ordinates divided by the difference in the x co-ordinates can't you?
That gives you the m in y=mx+c
now you just neet the y intercept for the c
you know the point C is on DC so you know values for x and y and you have m from step 1 so you can find c
That gives you the m in y=mx+c
now you just neet the y intercept for the c
you know the point C is on DC so you know values for x and y and you have m from step 1 so you can find c