ka,tolong di. jawab ya

1 a.
12,5° = 12° + (0,5 x 60)
= 12° + 30'
= 12° 30'

1b. 81,43°
= 81° + (0,43 x 60)
= 81° + 25' +(0,8 x 60)
= 81° + 25' + 48"
= 81° 25' 48"

1c. 30,84°
= 30° + (0,84 x 60)
= 30° + 50' + (0,4 x 60)
= 30° + 50' + 24"
= 30° 50' 24"

2a. 180°
[tex] = \frac{180}{180} \times \pi \\ = 3.14[/tex]

2b. 135°
[tex] = \frac{135}{180} \times \pi \\ = \frac{3}{4} \times \pi \\ = 2.36[/tex]

2c. 144°
[tex] = \frac{144}{180} \times \pi \\ = \frac{4}{5} \times \pi \\ = 2.51[/tex]

3a. 42° 24' 35"
= 42° + 24' + (35/60)
= 42° + 24' +0,58
= 42° + (24,58 / 60)
= 42° + 0,41
= 42,41°

3b. 5/6 phi
[tex] = \frac{5\pi}{6} \times \frac{180}{\pi} \\ = \frac{900\pi}{6\pi} \\ = {150}^{0} [/tex]

3c. 4 rad
[tex] = 4 \times \frac{180}{\pi} \\ = \frac{720}{\pi} \\ = {229.3}^{0} [/tex]
4a.
= 72° 34' 57" + 42° 43' 21"
= 114° 77' 78"
= (114° + 1°)((77'-60')+1')(78"-60")
= 115° 18' 18"

4b.
= 108° 13' 16" - 99° 41' 28"
= 108° 12' 76" - 99° 41' 28"
= 107° 72' 76" - 99° 41' 28"
= 8° 31' 48"

5a.luas persegi - luas lingkaran
luas persegi :
14 x 14 = 196 cm²

luas lingkaran :
[tex] = \pi \times {r}^{2} \\ = \frac{22}{7} \times 7 \times 7 \\ = 22 \times 7 \\ = 154 {cm}^{2} [/tex]

jadi, luas yang diarsir:
196 - 154 = 42 cm²

5b.keliling persegi -keliling lingkaran
keliling persegi :
14 x 4 = 56 cm

keliling lingkaran :
[tex] = 2 \times \pi \times r \\ = 2 \times \frac{22}{7} \times 7 \\ = 2 \times 22 \\ = 44 \: cm[/tex]
keliling daerah: 56 - 44 = 12 cm