tolong dijawab yaaa...

Pembahasan :
[tex] = \sqrt[2]{ {13}^{2} - {5}^{2} } \\ = \sqrt[2]{169 - 25} \\ = \sqrt[2]{144} = 12 = 6 [/tex]

Panjang EC
[tex] = \sqrt[2]{ {6}^{2} + {8}^{2} } \\ = \sqrt[2]{36 - 64} \\ = \sqrt[2]{100} = 10[/tex]
Opsi B

Maaf kalau salah :(

BD^2 = AB^2 - AD^2
BD^2 = 13^2 - 5^2.
BD^2 = 169 - 25
BD^2 = 144
BD = V144 = 12
DC = 1/2 x BD
DC = 1/2 x 12 = 6
EC^2 = ED^2 + DC^2.
EC^2 = 8^2 + 6^2
EC^2 = 64 +36
EC^2 = 100
EC = V100
EC = 10 cm