7. Verify that parallelogram ABCD with vertices A(–5, –1), B(–9, 6), C(–1, 5), and D(3, –2) is a rhombus by showing that it is a parallelogram with perpendicular diagonals.

Question

7.   Verify that parallelogram ABCD with vertices A(–5, –1), B(–9, 6), C(–1, 5), and D(3, –2) is a rhombus by showing that it is a parallelogram with perpendicular diagonals.

CTree · Accepted Answer

(y2-y1)/(x2-x1) that is the formula

Reiny · Answer

easy,
after making sketch, show that the slopes of opposite sides are equal.
Then draw the diagonals and find their slopes
show that the slope of one diagonal is the opposite reciprocal of the slope of the other.
Be careful in your slope calculations with the subtraction of all those negative numbers

I will do one slope
slope AB = (6-(-1))/(-9 - (-5)) = 7/-4 or -7/4

CTree · Answer

what she needs is the formula...(that is helping not doing the work)

Student · Answer

Thanks CTree for the formula