Answer:
(13) The third side is 14 cm
(13) The third side is 16.1 cm
Step-by-step explanation:
Given
(13) & (14)
Required
Solve
(13): Let length AB = x.
Using Pythagoras theorem.
[tex]x^2 = 12^2 + 9^2[/tex]
[tex]x^2 = 144 + 81[/tex]
[tex]x^2 = 225[/tex]
Take positive square root of both sides
[tex]x = \sqrt{225[/tex]
[tex]x = 15[/tex]
(14): Let length DE = x.
Using Pythagoras theorem.
[tex]x^2 = 8^2 + 14^2[/tex]
[tex]x^2 = 64 + 196[/tex]
[tex]x^2 = 260[/tex]
Take positive square root of both sides
[tex]x = \sqrt{260[/tex]
[tex]x = 16.1[/tex] ---approximated
