Question

question 2
2.1 for each of the following questions, give only the correct reason for the corresponding statement.
(5)
statement\treason
2.1.1
$x + 40^{circ}=180^{circ}$

2.1.2
$a + b + c + d = 360^{circ}$

2.1.3
$e + f = 180^{circ}$

2.1.4
$e = g$

2.1.5
$i = g$

Explanation:

In 2.1.1, angles on a straight line add up to 180°. In 2.1.2, the total of all angles around a single point is 360°. In 2.1.3, co - interior angles formed by a transversal intersecting two parallel lines sum to 180°. In 2.1.4, corresponding angles with parallel lines and a transversal are congruent. In 2.1.5, alternate interior angles with parallel lines and a transversal are equal.

Answer:

2.1.1: Supplementary angles on a straight - line.
2.1.2: The sum of angles around a point is 360°.
2.1.3: Co - interior angles between parallel lines are supplementary.
2.1.4: Corresponding angles between parallel lines are equal.
2.1.5: Alternate interior angles between parallel lines are equal.