Question

Plis jawab nomor 1 dan 2
pakai cara
pointnya banyak ​

Answer 1

1)
L = luas trapesium - luas setengah lingkaran

L = 1/2 (30+ 51) x 28 - (1/2 x 22/7 x 14²)

L = 1134 - 308 = 826cm²

Sisi miring
= √28² + 21²
= √784 + 441
=√1225
= 35cm

K = 30+21+35+30+ (1/2 x 22/7 x 28)

K = 116 + 44 = 160cm

2)
luas = 1/2 πr²
luas = 1/2 x 22/7 x 21² = 693cm²

K = 1/2 x 22/7 x 42 + 42 = 108cm

Answer 2

1. Luas 1

= ½ x (30 + 51) x 28

= ½ x 81 x 28

= 1.134 cm²

Luas 2

= ½ x 22/7 x 14 x 14

= 308 cm²

Luas = 1.134 cm² – 308 cm²

= 826 cm²

Sisi miring segitiga

= √28² + 21²

= √784 + 441

=√1.225

= 35 cm

K = 30 x 2 + 21 + 35 + (1/2 x 22/7 x 28)

K = 116 + 44 = 160 cm

2. Luas ½ lingkaran

= ½ x 22/7 x 21 x 21

= 693 cm²

Luas ½ lingkaran yang dibawah

= ½ x 22/7 x 7 x 7 

= 77 cm²

Luas = 693 cm² – 77 cm²

= 616 cm²

Keliling  = 14 + 14 + ½ x 22/7 x 42 + ½ x 22/7 x 14

= 28 cm + 66 cm + 22 cm

= 116 cm

Mapel: Matematika

Kelas: SD/SMP

Materi: Luas dan Keliling