The length of DE is 4.24 unit.
Pythagoras theorem :
- It states that in a right-angled triangle, the square of the hypotenuse is equal to the sum of the squares of the other two sides.
- A right angle triangle DFE is given , in which angle F is 90 degrees.
Given, D F = E F = 3
Apply Pythagoras theorem,
[tex]DE^{2}=DF^{2} +EF^{2}\\ \\ DE^{2}=3^{2}+ 3^{2}\\\\DE=\sqrt{9+9}=\sqrt{18} =4.24[/tex]
The length of DE is 4.24 unit.
Learn more about the right angle triangles here:
https://brainly.com/question/64787
