Chapter 9.7, Problem 23PSB

To determine

To calculate: The New coordinates of E .

Answer to Problem 23PSB

New coordinates of E are $(0,2\sqrt{5})$ .

Explanation of Solution

Given information:Here, we have given a rectangle RECT and it is rotated to the origin until E lies on positive y axis.

Formula used: Distance formula: d = $\sqrt{{(x_2-x_1)}^2+{(y_2-y_1)}^2}$

Calculation: Join OE.

Coordinates of E are $(2,4)$ and O are $(0,0)$ .

OE = $\sqrt{{(2-0)}^2+{(4-0)}^2}$

  $\begin{array}{l}\Rightarrow \sqrt{{(2)}^2+{(4)}^2}\\ \Rightarrow \sqrt{4+16}\\ \Rightarrow \sqrt{20}\\ \Rightarrow 2\sqrt{5}\end{array}$

  $\therefore$ y = $2\sqrt{5}$

  $\Rightarrow$ New coordinates of E are $(0,2\sqrt{5})$