Maths Y09 Aut1

Question 1

1 Pi (π)

Answer 1

The ratio of a circle’s circumference to its diameter. The symbol is π, and π =3.141 to 2 decimal places

Question 2

1.1 Radius

Answer 2

A line that goes from the centre to the circumference. It is half the length of the diameter

Question 3

1.2 Diameter

Answer 3

A line that passes through the centre of the circle. It is double the length of the radius

Question 4

1.3 Circumference of a circle

Answer 4

The outside of the circle. The perimeter of the circle. C=2πr=πd

Question 5

1.4 Area of a circle

Answer 5

A=πr^2

Question 6

1.5 Chord

Answer 6

A line segment connecting two points on a circle

Question 7

1.6 Sector

Answer 7

An AREA within a circle bounded by a chord and an arc. Area of a sector= angle/(360°)×πr^2

Question 8

1.7 Segment

Answer 8

An AREA within a circle bounded by a chord and an arc. The smaller area is the minor segment and the larger area is the major segment

Question 9

1.8 Arc

Answer 9

Part of the circumference between two points. Arc length=( angle)/(360°)×πd

Question 10

1.9 Tangent

Answer 10

A straight line that touches the circle at one point.

Question 11

3 Bearing

Answer 11

An angle, measured clockwise from north line, has 3 digits. E.g. 30° clockwise from north is written as 030°

Question 12

3.1 Compass directions rotating 90 degrees clockwise from North

Answer 12

North, East, South, West

Question 13

3.2 Hypotenuse

Answer 13

The longest side of a right-angled triangle. The hypotenuse is always opposite the right-angle

Question 14

3.3. Opposite

Answer 14

The side opposite the given angle in a right-angled triangle

Question 15

3.4 Adjacent

Answer 15

The side next to (touching) the given angle in a right-angled triangle

Question 16

3.5 sin⁡θ

Answer 16

sin⁡〖θ=o/h〗

Question 17

3.6 cos⁡θ

Answer 17

cos⁡〖θ=a/h〗

Question 18

3.7 tan⁡θ

Answer 18

tan⁡〖θ=o/a〗

Question 19

3.8 Pythagoras’ theorem

Answer 19

a^2+b^2=c^2 Where ‘c’ is always the hypotenuse

Question 20

3.9 Should we use Pythagoras or trigonometry?

Answer 20

Both require a right angled triangle. We use Pythagoras when we are only working with side lengths. We use trigonometry when we have or are asked to find an angle

Question 21

4 Equation of a circle with centre (0, 0) and radius ‘r’

Answer 21

x^2+y^2=r^2

Question 22

4.1 Ratio

Answer 22

Ratio compares the size of one part to another

Question 23

4.2 Proportion

Answer 23

Proportion compares the size of one part to the size of the whole. (Usually written as a fraction)

Question 24

4.3 Simplifying ratios

Answer 24

Divide all parts of the ratio by a common factor.1. Add the total parts of the ratio.2. Divide the amount to be shared by this value to find the value of one part.3. Multiply this value by each part of the ratio.

Question 25

4.5 Direct Proportion

Answer 25

When one variable increases as the other increases.

Question 26

4.7 Inverse Proportion

Answer 26

When one variable decreases as the other increases.

Question 27

2.0

Answer 27

Radius

Question 28

2.1

Answer 28

Diameter

Question 29

2.2

Answer 29

Chord
(the diameter is a special chord)

Question 30

2.3

Answer 30

Arc

Question 31

2.4

Answer 31

Tangent

Question 32

2.5

Answer 32

Sector

Question 33

2.6

Answer 33

Segment