Penjelasan dengan langkah-langkah:

1) Dik : K persegi = 72cm

Dit : L persegi = ?

Jwb :

K persegi = 4×sisi

72 cm = 4×s

72/4 cm = s

s = 18 cm

L persegi = s²

L = 18² cm²

L = 324 cm²

2) Dik : L persegi = 196 cm²

Dit : K persegi = ?

Jwb :

L persegi = s

196 cm² =

s = √196 cm

s = 16 cm

K = 4×s

K = 4×16 cm

K = 4×16 cm

K = 54 cm

3)

K = 2(p+l)

36 cm = 2(p+l)

p+l = 36/2 cm = 18 cm

p = 5/9 × 18 cm = 10 cm

l = 4/9 × 18 cm = 8 cm

L = p × l

L = 10 cm × 8 cm = 80 cm²

4)

L = p × l

p × l = 240 cm²

5n × 3n = 240 cm²

15n = 240 cm²

n = 240/15 cm²

n = √16 cm²

n = 4 cm

p = 5n = 20 cm

l = 3n = 12 cm

K = 2(p+l)

K = 2(20 cm + 12 cm)

K = 2 × 32 cm

K = 64 cm

Mohon koreksi apabila ada yang salah (^_^)