Angles

A lesson on angles, including with circle theorems in it!

1. Angles revision….

2. What is significant about the letters F, Z, C
and U in this topic?
Write down the answer in your books, with
an illustration if possible.
What about x?
Angles

3. Interior angles
These are angles inside a polygon.
They add up to (n-2) x 180 where n is the number of sides
Interior angles
What do these angles add up to?

4. Exterior angles
Add up to 360

5. Angles on a straight line
Angles to a point

6. Vertically opposite angles

7. Parallel
Lines
a
77
a = 77 because
a and 77 make
an F.

8. Parallel
Lines
a
77
a = 77 because
a and 77 make
an F.
“F” angles are called corresponding angles

9. Parallel
Lines
a
77
a = 77 because
a and 77 make
a Z

10. Parallel
Lines
a
77
a = 77 because
a and 77 make
a Z.
“Z” angles are called alternate angles

11. p.18 Ex2A Q1, 10 – 15
p.19 Ex2B Q1, 4, 11, 12
p.20 Q13-15
p.21/ 22 Ex2C Q1, 6, 7, 12, 13, 14, 16-20
p.24/ 25 Ex2D Q1, 4, 10, 14, 16
p.28 Ex2E Odd Questions
p.30 Ex2F Even Questions
p.32 Ex2G – All questions

12. Circles
chord
Centre of circle to a
Chord – meets at
Right angles

13. tangent
Radius to a tangent – meets at right
angles

14. Cyclic quadrilaterals –
Opposite angles add up to 180

15. An angle subtended by a semi
Circle is a right angle
90

16. Angles from the same point
to the middle are twice those
at the circumference
x
2x

17. Angles in the same segment are equal
x
x