Pls someone explain this to me

Thank u.

a) a= 60

c) a= 135

d) a= 40

f) a= 115

g) a= 37

i) a= 130

Step-by-step explanation:

If you see a little square at the angle, this means that the angle is a right angle, which means that it is 90°.

Let's look at Q5a.

a) a° +30°= 90°

a°= 90° -30°

a°= 60°

a=60

Questions 5b has the same concept.

The sum of the angles on a straight line is 180°. The abbreviation used for this is (adj. ∠s on a str. line).

Let's look at Q5c.

c) a° +45°= 180° (adj. ∠s on a str. line)

a°= 180° -45°

a°= 135°

a= 135

Question 5d uses the same concept too.

Let's look at Q5d.

d) 90° +50° +a°= 180° (adj. ∠s on a str. line)

a°= 180° -90° -50°

a°= 40°

a= 40

Vertically opposite angles are equal. The abbreviation written for this is (vert. opp. ∠s).

Use this for questions 5f and 5g.

f) a°= 115° (vert. opp. ∠s)

a= 115

g) a°= 37°

a= 37

The sum of angles on a point is 360°. This will help you solve questions 5h and 5i.

i) 140° +90° +a° = 360° (∠s at a point)

a° +230°= 360°

a°= 360° -230°

a°= 130°

a= 130