Tolong di kerjain kak 1-4​

jawaban  dengan langkah-langkah:

1 keliling= 12+10+10= 32 cm

luas= alas kali tinggi / 2

12 kali 8 / 2 =48 cm

2 keliling =  15 +17 + 8= 40 cm

luas = 15 kali 8 /2 =60 cm

3 keliling= 13 + 15 + 5+ 9=42 cm

luas = 5 kali 12/2=30 cm

12 kali 9 / 2 = 54cm

54 + 30= 84

4. keliling= 10+ 9+17= 36cm

luas = 15 kali 8/2= 60cm

6 kali 8/2=24

60-24=36cm

Rumus

Keliling = Jumlah sisi ketiga segitiga = sisi A + sisi B + sisi C

Luas = 1/2 x Alas x Tinggi = 1/2 x a x t

Soal 1

Keliling = sisi A + sisi B + sisi C

= 10 cm + 12 cm + 10 cm ( sisi A = sisi C )

= 32 cm

( alas = sisi B = 12 cm,

tinggi = 8 cm )

Luas = 1/2 x a x t

= 1/2 x 12 cm x 8 cm

= 1/2 x 96 cm²

= 96/2 cm²

= 48 cm²

Soal 2

Keliling = sisi A + sisi B + sisi C

= 15 cm + 8 cm + 17 cm

= 40 cm

( alas = sisi B = 8 cm,

tinggi = sisi C = 15 cm )

Luas = 1/2 x a x t

= 1/2 x 8 cm x 15 cm

= 1/2 x 120 cm²

= 120/2 cm²

= 60 cm²

Soal 3

Keliling = sisi A + sisi B + sisi C

= 13 cm + (5+9) cm + 15 cm

= 13 cm + 14 cm + 15 cm

= 42 cm

( alas = sisi B = 14 cm,

cm, tinggi = 12 cm )

Luas = 1/2 x a x t

= 1/2 x 14 cm x 12 cm

= 1/2 x 168 cm²

= 168/2 cm²

= 84 cm²

Soal 4

Keliling = sisi A + sisi B + sisi C

= 17 cm + 9 cm + 10 cm

= 36 cm

( alas = sisi B = 9 cm,

tinggi = 8 cm )

Luas = 1/2 x a x t

= 1/2 x 9 cm x 8 cm

= 1/2 x 72 cm²

= 72/2 cm²

= 36 cm²

Sekian dan terima kasih :)