Answer:
see explanation
Explanation:
(h)
the 3 angles lie on a straight line and sum to 180°
sum the 3 angles and equate to 180
x - 1 + 2x + 1 + x + 20 = 180 ← simplify left side
4x + 20 = 180 ( subtract 20 from both sides )
4x = 160 ( divide both sides by 4 )
x = 40
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k
20° and x are a linear pair and sum to 180°
x + 20° = 180° ( subtract 20 from both sides )
x = 160°
y and 20° are vertically opposite angles and are congruent , so
y = 20
z and x are vertically opposite angles and are congruent , so
z = x = 160
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l
3a and a are a linear pair and sum to 180° , that is
3a + a = 180
4a = 180 ( divide both sides by 4 )
a = 45 and 3a = 3 × 45 = 135
a and x are vertically opposite angles and are congruent , so
x = a = 45
3a and y are vertically opposite angles and are congruent, so
y = 3a = 135