Dik panjang alas segitiga sama kaki 18cm . Apabila luas segitiga 108cm² ,maka keliling segitiga tsb adalah, pakai cara

L = 1/2 × a × t
108cm2 = 1/2× 18cm × t
108cm2 = 9cm
T= 108/9
= 12cm
k = 1/2 ×( a + t)
= 1/2 ×( 18 + 12 )
= 1/2 × 30
= 15 cm