Hitunglah luas permukaan pada bangun ruang berikut ​

Jawaban:

> garis pelukis

= √21² + 28² = √441 + 784

= √1225

= 35 cm

> Lp kerucut

= π × r (r + s)

= 22/7 × 28 × (28 + 35)

= 88 × 63

= 5.544 cm²

> Lp bola

= 4 × π × r² × 1/2

= 4 × 22/7 × 28 × 28 × 1/2

= 4.928 cm²

Lp gabungan

= Lp kerucut + Lp bola – 2 sisi berhimpit

= 5.544 + 4.928 – (2 × ( π.r.r))

= 10.472 – (2 × (22/7 × 28 × 28))

= 10.472 – 4.928

= 5.544 cm²