tolong jawab ya sma cra nya

1. a. siku2
b. tumpul
c. lancip
d. lurus
e. reflek
f . 2/5 × 90 = 36 ° = lancip
g. 3/9 × 180 = 60° = lancip
h. 2/12 × 360 = 60° = lancip

2. setahuku
a. 90-35 = 55°
b. 180-78 = 102°

3. a. 180° = 90 + 5x-10 + 7x-20
180° = 90 + 12x -30
180° - 60 = 60 + 12x - 60
120° = 12x
10 = x

b. AOD = 7x - 20
= 7×( 10) - 20
= 70 - 20 = 50°
c. DOC = 90°
d. COB = 5x - 10
= 5×(10) - 10
= 50 - 10
= 40°