1. Name the coordinates of points A, B, and C.
2. Name the coordinates of a point D such that$\mathrm{\Delta }ABC\cong \mathrm{\Delta }ABD$.

Coordinate$\left(x,y\right)$ of a point is an ordered pair of numbers; that is, a number on the x-axis called anx-coordinate, and a number on the y-axis called a y-coordinate.

Steps to find the coordinate of point$A$are:

• Point$A$is 1 unit away from origin in positive $x$axis. Thus, the x-coordinate is 1.
• Then, point $A$is 2 units away from origin in positive $y$axis. Thus, the y-coordinate is 2.

Steps to find the coordinate of point$B$are:

• Point$B$is 4 units away from origin in positive $x$axis. Thus, the x-coordinate is 4.
• Then, point $B$is 2 units away from origin in positive $y$axis. Thus, the y-coordinate is 2.

Steps to find the coordinate of point $C$are:

• Point $C$is 2 units away from origin in positive $x$axis. Thus, the x-coordinate is 2.
• Then, point $C$is 4 units away from origin in positive $y$axis. Thus, the y-coordinate is 4.

Therefore, coordinates of points are $A=\left(1,2\right)$, $B=\left(4,2\right)$and $C=\left(2,4\right)$.

Coordinate$\left(x,y\right)$ of a point is an ordered pair of numbers; that is, a number on the x-axis called anx-coordinate, and a number on the y-axis called a y-coordinate.

The two triangles are said to be congruent if they are copies of each other and if their vertices are superposed, then can say that the corresponding angles and the sides of the triangles are congruent.

In order to find a coordinate of point $D$ such that $\mathrm{\Delta }ABC\cong \mathrm{\Delta }ABD$, point$D$ should be such that triangles$\mathrm{\Delta }ABC$ and$\mathrm{\Delta }ABD$ should superpose. Therefore, such coordinates of point$D$ is $\left(2,0\right)$.