keliling42 panjang 15 lebar?

Keliling Persegi Panjang = 2p + 2l
42 = 2(15) + 2(l)
42 = 30 + 2l
42 - 30 = 2l
12 = 2l
12/2 = l
6 = lebar.

keliling = 2 × ( p + l )
= 2 × ( 45 + 15 )
= 2 × 60
= 120 cm



semoga membantu.....