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Place two sides along the coordinate axes.
The sides of the rectangle are parallel to the coordinate axes.
Use the names of the vertices.
Use the Distance Formula.
Diagram:
Q(0,q), R(s,q), S(s,0)
Statements:
2 &Given:&& PQRS is a rectangle &Prove:&& PR≅QS
See solution.
Since the angles of a rectangle are right angles, we can place PQRS in the coordinate plane with two sides on the coordinate axes.
Let's think about the relationship between the coordinates of P, Q, R, and S.
Let's use variables to name the coordinates of Q, R, and S.
These are just example variables, so your variable choices may differ.
It is given that PQRS is a rectangle, and the claim is that the diagonals are congruent.
To show that two segments are congruent, it is enough to show that they have the same lengths. In a coordinate proof we can use the Distance Formula to express the length of a segment in terms of the coordinates of the endpoints.
The distance
between points(x_1,y_1)and(x_2,y_2)is
sqrt((x_2-x_1)^2+(y_2-y_1)^2).
Substitute ( 0,0) & ( s,q)
Subtract terms
Similarly, we can find the length of diagonal QS.
Substitute ( 0,q) & ( s,0)
Subtract terms
(- a)^2=a^2
We can see that PR=QS, so the diagonals of rectangle PQRS are indeed congruent.