# 11.06 Coordinate methods with quadrilaterals

## Interactive practice questions

The points given represent three vertices of a parallelogram. What is the fourth vertex if it is known to be in the 2nd quadrant?

Coordinates $=$=$\left(\editable{},\editable{}\right)$(,)

Easy
Approx 2 minutes

The points given represent three vertices of a rhombus. What is the fourth vertex if the missing point lies in the 3rd quadrant?

$A$A$\left(-3,-4\right)$(3,4), $B$B$\left(-5,2\right)$(5,2) and $C$C$\left(-11,0\right)$(11,0) form three vertices of square $ABCD$ABCD, where $T$T is the midpoint of the diagonal $AC$AC, and vertex $D$D is represented by the coordinates $D$D$\left(p,q\right)$(p,q).

Consider the parallelogram $ABCD$ABCD that has been graphed on the number plane.

### Outcomes

#### II.G.GPE.4

Use coordinates to prove simple geometric theorems algebraically.