1. a) 0, b) 90° c) <90°
2. a) 360:3 = 120° fiecare unghi
c) m∡1 + m∡2= 180
m∡1 = 2x m∡2
2x m∡2+m∡2 = 180
3m∡2 = 180
m∡2 = 180:3 = 60°
3. ∡ABD + ∡CBD = 153°27' + 26°33'= 179°60'= 180
DECI m∡ABC = m∡aABD +m∡CBD = 180° => A,B,C SUNT COLINIARE
5. m∡AOB = m∡AOC+m∡COB, OC fiind fiinx axa de simetrie = > m∡AOC = m∡COB
m∡AOB = 14°30' +14°30'=28°60'=30°
6. a) 23°10'+31°2'+10°23'=64°35'
b) 175°-134°20'+630':3x2=174°60'-134°20'+210'x2 = 40°40'+420'= 40°40'+7°
=47°40'
c) (1°+2°+3°+..+13°) - 90° =13°x14°: 2-90=182° : 2-90°=92°-90° = 2°
d) (1°+2°+3°+..+14°) : 21+ 85° = 14° x15° : 2 : 21 + 85° = 210°: 2 : 21 +85°=
=105°:21 + 85° = 5° + 85° = 90°
e) 1°1'+2°2'+3°3'+ ...+16° 16'= (16°x17°: 2) (16'x17':2) = 272°:2 + 272':2
=136°136' = 136°+2°16'=138°16'
La c, d, e am aplicat suma lui Gauss.
f) 180° - (2°2'+22°22'-24°24') - (40°40'-40') = 180° - 0-40°= 140°
7. a) 6'
b) 45'
c) 21'
d) 13°20'=13x60'20'=780'+20'=800', 800x15:100=120'
e) 324'
f ) 3'
