Nomor lima

p : l = 3 : 5

maka :

=> P = 3x

=> l = 5x

=> Luas = p ( l )

=> 135 = 3x ( 5x )

=> 135 = 15 ( x . x )

=> 135 = 15x²

=> x² = 135/15

=> x² = 9

=> x = √9

=> x = 3 cm

Panjang

=> 3x

=> 3 ( 3 )

=> 9 cm

Luas

=> 5x

=> 5 ( 3 )

=> 15

maka keliling nya yaitu :

=> 2 × ( p + l )

=> 2 × ( 9 + 15 )

=> 2 × 24

=> 48 cm ( D )

_____________________

Nomor enam

=> s² = a² + t²

=> 5² = 6² + 4²

=> 25 = a² + 16

=> a² = 25 - 16

=> a² = 9

=> a = √9

=> a = 3 cm

Maka luas nya yaitu :

=> ½ × a × t

=> ½ × 6 × 4

=> 6/2 × 4

=> 3 × 14

=> 42 cm²