the point of intersection of the diagonals of a quadrilateral divides one diagonal in the ratio 4:5. is it parallelogram ?

nope. diagonals of a parallelogram bisect each other.

To determine if the quadrilateral is a parallelogram, we need to check if its opposite sides are parallel. However, knowing the ratio in which the point of intersection of the diagonals divides one diagonal is not sufficient to determine if the quadrilateral is a parallelogram.

To confirm whether the quadrilateral is a parallelogram or not, we need additional information. One possible approach is to examine the diagonals' ratios on the opposite side of the quadrilateral.

Here's how you can proceed:

1. Consider a quadrilateral with diagonals AC and BD, intersecting at point O.

2. Given that the point of intersection O divides diagonal AC in the ratio 4:5, we can express this as follows:

AO:OC = 4:5

3. Similarly, consider the ratio in which O divides diagonal BD. Let's assume it is p:q:

BO:OD = p:q

Now, to determine if the quadrilateral is a parallelogram, we need to find the relationship between the chosen ratios p:q and 4:5.

4. Apply the property of intersecting lines: The product of the ratios of corresponding segments formed by the intersecting lines is equal.

Using this property, we can write the equality:

AO/OC * BO/OD = 1

Substituting the given ratios, we have:

(4/5) * (p/q) = 1

5. Simplify the equation by cross-multiplying:

4q = 5p

6. The resulting equation, 4q = 5p, provides a relationship between the ratios. From this equation, we can determine if the opposite sides are parallel.

If the equation holds true for all possible values of p:q, then the opposite sides are parallel, and the quadrilateral is a parallelogram.

If the equation does not hold true for any values of p:q, then the opposite sides are not parallel, and the quadrilateral is not a parallelogram.

By solving the equation, you can determine if the given quadrilateral is a parallelogram or not.