Keliling segitiga ABC adalah ..cm

phytagoras alas = 9 cm
Maka keliling = 9+9+15+15
= 48 cm (D)

BD = AD = √15² - 12²
BD = AD = √225 - 144
BD = AD = √81
BD = AD = 9 cm

AB = 9 cm + 9 cm = 18 cm
AC = BC = 15 cm

K = AC + AB + BC
K = 15 cm + 18 cm + 15 cm
K = 48 cm (D) ✔