Hai…

5) D (Rumus : c² = a² + b²)

6) x = 5 + 7 = 12 y = -6-3 = -9
jarak = √x² + y²
jarak = √144 + 81 = √225 = 15cm

7)
AD//AB = √12² + 16² = √144 + 256
= √400 = 20cm

EC = √13² – 12² = √169-144 = √25 = 5cm

K = 20+20+13+13 = 66cm