Question

LINGKARAN
Juring dengan sudut pusat 30° pada lingkaran yang berdiameter 28 cm.
tentukan Luas tembereng ?

Answer 1

Luas tembereng = 18,7 cm²

Penjelasan dengan langkah-langkah:

Jari jari:

[tex] = d \div 2[/tex]

[tex] = 28 \div 2 = 14 \: cm[/tex]

luas juring:

[tex] \displaystyle \frac{ \theta}{360\degree} \times (\pi \times {r}^{2} )[/tex]

[tex] = \displaystyle \frac{ 30 \degree }{360\degree} \times ( \frac{22}{7} \times {14}^{2} )[/tex]

[tex] = \displaystyle \frac{ 30 \degree }{360\degree} \times (22 \times 14 cm \times 2 )[/tex]

[tex] = \displaystyle \frac{ 1 \degree }{12\degree} \times ( 22 \times 14 cm)[/tex]

[tex] = \displaystyle \frac{ 1 \degree }{12\degree} \times ( 308 cm^{2})[/tex]

[tex] = \displaystyle 51, 3 cm^{2}[/tex]

luas segitiga:

= ½ x alas x tinggi

= ½ x 14 x 14

= 98 cm² ÷ 3

= 32,6 cm²

luas tembereng:

= 51, 3 cm² - 32,6 cm²

= 18,7 cm²

Answer 2

Verified answer

Jawab:

Penjelasan dengan langkah-langkah:

Komponen Lingkaran

Lj

= 30/360 × (22/7 × 14 × 14)

= 1/12 × (22 × 14 × 2)

= 1/12 × (616)

≈ 616/12

= 154/3 cm²

Luas segitiga aturan sinus

= ½.AC.AD.sinA

= ½.14.14.sin30°

= 98.½

L.Tembereng

= 154/3 - 98/2

= 308/6 - 294/6

= 14/6

= 7/3

= 2⅓ cm²