Shape

Question 1

Perimeter = ?

Answer 1

Total length around the outside of a shape

Question 2

Area = ?

Answer 2

The total space inside the shape

Question 3

What is area measured in?

Answer 3

Cm^2

Question 4

How do you work out area of a rectangle?

Answer 4

Base x height

Question 5

How do you work out area of a triangle?

Answer 5

(Base x perpendicular height) /2

Question 6

How do you work out area of a parallelogram?

Answer 6

Base x perpendicular height

Question 7

In a circle, what is origin?

Answer 7

Centre of circle

Question 8

In a circle, what is arc?

Answer 8

A part of the circumference

Question 9

In a circle, what is tangent?

Answer 9

Touches circumference at one point

Question 10

In a circle, what is chord?

Answer 10

Line that goes across, but not through the middle of circle

Question 11

In a circle, what is sector?

Answer 11

Has to go from the centre

Question 12

In a circle, what is circumference?

Answer 12

The distance around the edge of a circle

Question 13

In a circle, what is diameter?

Answer 13

The distance from one edge of the circle to the other, passing through the centre

Question 14

In a circle, what is radius?

Answer 14

The distance from the centre of the circle to the edge

Question 15

What is the equation for circumference?

Answer 15

2x(Pi)xradius

Question 16

Circle has a radius of 2.1m. What’s the circumference?

Answer 16

R =2.1m
C = 2pir
C =2 x pi x 2.1
/calculator
C = 13.2m

Question 17

A circle has a diameter of 6mm. What is the circumference? Leave your answers in terms of pi.

Answer 17

Diameter = 6mm radius = 3mm
C =2pir
C = 2x pi x 3
C= 6 pi mm

Question 18

When should we leave our answer in terms of pi? Why?

Answer 18

During a multi step question, to avoid rounding errors

Question 19

A circle has a circumference of 14m. What is the diameter?

Answer 19

C = 2 pi r
14 = 2 pi r
/ divide by 2 pi
14/2 pi = r
2.23m = r

Question 20

A bicycle wheel has a diameter of 80cm. How many revolutions does the wheel do around a 400m track?

Answer 20

Revolution = 1 circle of the wheel
1 revolution = circumference
C = 2 pi r
C =2 x pi x 40
C = 80 pi cm
R = 80 / 2 = 40cm

Track = 400m x 100 = 40, 000 cm
Revolutions = 40000 / 80pi = 159.2 revolutions

Question 21

How do you work out the area of a circle?

Answer 21

Area = r^2 x pi

Question 22

Work out the area of a circle with a diameter of 20cm

Answer 22

R = 20/2 = 10
A= 10^2 x pi
=314.2cm^2

Question 23

Your shape is a rectangle with a semi circle at one end. Work out the perimeter and area of the shape, when the base is 40cm and the height of the rectangle is 80cm

Answer 23

Perimeter
Semicircle = (2xpixr)/2 = (2xpix20)/2 = 20pi
Leave in terms of pi to avoid a rounding error
P=80+80+40+20pi
=200+20pi
=262.8cm

Area
Rectangle: 80x40=3200cm^2
Semicircle: (pixr^2)/2 = (pix20^2)/2 = 200pi cm^2
A= 3200+200pi
=3828.3cm^2

Question 24

What is a trapezium?

Answer 24

A 4 sided shape with 1 pair of parallel lines

Question 25

How do you work out the area of a trapezium?

Answer 25

(a+b)/2xh

(Parallel side + parallel side)/2 x perpendicular height

Question 26

Find the area of a trapezium. Parallel sides: 5cm and 6cm. Perpendicular height:3cm.

Answer 26

Area = (5+6)/2 x3

=16.5cm^2

Question 27

Calculate one length of a square of an area 196cm^2

Answer 27

X^2 = 196cm
Square root of 196 = x
X=14cm

Question 28

What is a sector?

Answer 28

A section of a circle, starting from ten centre.

Question 29

Find the area of a sector of a circle, where the bottom length is 10cm and the angle next to the centre is 70*

Answer 29

You have 70/360 of a circle 
Area = pi x r^2
=70/360 x pi x 10^2
= 61.0865...
=61.1cm^2

Question 30

Find the perimeter of a sector where the base length is 10cm, and the angle next to the centre is 70*

Answer 30

Circumference = 2 x pi x r
70/360 x 2 x pi x 10
= 12.2173…

Perimeter = 12.2173… + 10 + 10
= 32.2173…