Answer:
1) x= 15
2) x= 34
3) x= 40
Explanation:
1) 4x°= 45° +15° (vert. opp angles)
4x°= 60° (simplify)
x°= 60° ÷4 (÷4 on both sides)
x°= 15°
Thus, x= 15.
2) (x+12)° +100° +x°= 180° (adj. angles on a str. line)
2x° +12°= 180° -100°
2x°= 80° -12°
2x°= 68°
x°= 68° ÷2
x°= 34°
x= 34
3) 3x°= 120° (vert. opp. angles)
x°= 120° ÷3
x°= 40°
x= 40
Abbreviations:
1. vert. opp. angles
- vertically opposite angles
- This means that when 2 straight lines intersect, the angles facing opposite each other are equal.
2. adj. angles on a str. line
- adjacent angles on a straight line
- the sum of the angles that lie on a straight line is 180°