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=Welcome to our New Wiki for Yr. 10 Mathematics!=

**The first topic this term is __'Measurement'__ and by now you have completed the introductory booklet to refresh your memmory on**

 * converting units
 * calculating perimeter of different shapes
 * calculating the area of squares, rectangles, & right angles triangles

The next unit of work relating to measurement that will be investigated is **Ratio and Scale**.

Read & study the following practice excercise to familiarise yourself with ratios and scale and how to complete to preceeding questions

If a plan represents a real length of 3m by 1.5cm, calculate the scale factor.
Steps.
 * Convert the two measurements to the same units... 3m = 300 cm, 1.5 m = 1.5cm


 * Write these lengths as a ratio ... 300 : 1.5


 * Write the ratio as a fraction ... scale factor = 300/ 1.5


 * Simplify as necessary... scale factor = 200

**TASK1** Use the above steps to complete the following plan measurements to determine the scale factor.

1. 10 mm represents 1 km

2. 5 cm represents 500m

3. 2.5 cm represents 50 m

4. 15 mm represents 300 km

5. 3 cm represents 3 m

6. 23 mm represents 460 000 km

Maps and plans are similar to real objects and they are related by a scale factor. We can also try to apply this skill of using scale to determine actual distances &/or lengths.

To do this we will be using google maps to locate particular sites around the school and determine their distance (including appropriate units) from Woodville hs.

**TASK 2** Use the following link and follw the instructions to complete this task. media type="googlemap" key="http://maps.google.com/maps?source=s_q&hl=en&geocode=&q=woodville+high+school&aq=&sll=37.0625,-95.677068&sspn=24.594583,45.175781&ie=UTF8&hq=woodville+high+school&hnear=Adelaide+South+Australia,+Australia&split=1&t=h&ll=-34.871315,138.540168&spn=0.126074,0.131541&output=embed" width="425" height="350"

Zoom in onto the map until the scale reads 200m and answer the following questions.

Measure the distance from Woodville High School and the following locations.

1. Islamic Arab Centre & Al Khalil Mosque

2. City Shelving

3. Evans Clarke Dominion

4. Unifresh

**TASK 3** Select a buliding on the school site (which has allready been done for you) and determine its dimensions using the Scale.

[|measurement map scale.notebook] Calculate the perimeter of this building and the area it ocupies at groun level.

When you have calculated the theoretical dimensions of the building (length & width ), compare the values with actual measurements made by class members.

Tabulate all your results using metres and millimetres.

How do the two measrements (google maps/ scale ratio and hands- on measuring compare)? Discuss.

What did you use to measure the building? What other devices may be used to measure the length and the width of a building? Research on line practical measuring devices used to determine lengths and widths.

**TASK 4**

Write in words how __you__ can __check__ that this is a true statement.
What equipment and information do you need?

Show the measurements you made of the toy for the following specifications (dont forget the units of your measurements):

.[[file:hummer.docx]]
A diagram that may assist with your measurements.



=**Circumference of circles.**= **C = π d **  **C = 2πr **    Use the above equations to solve the following questions  **﻿** Find to two decimal places, the circumference of a circle of: a) diameter 13.8 m b) radius 3.7km c) diameter 13.2 cm d) radius 8.6m e) diameter 115m f) radius 0.85m g) diameter 7.2m h) radius 235cm [|circumference]  let's find the perimeter of this semicircular pond. hint: = =  <span style="background-color: transparent; color: #000000; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;">Problem 1; Find the perimeter of this shape. Find the perimeter of this shape. Find the perimeter of this flower bed. <span style="background-color: transparent; color: #000000; display: block; font-family: 'Times New Roman'; font-size: 16px; text-align: left; text-decoration: none;"> > <span style="background-color: transparent; color: #000000; display: block; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;"> <span style="background-color: transparent; color: #000000; display: block; font-family: Times New Roman; font-size: 32px; text-align: left; text-decoration: none; vertical-align: auto;">**<span style="background-color: transparent; color: #000000; font-family: Times New Roman; font-size: 32px; text-align: left; text-decoration: none; vertical-align: auto;">Area of circles. ** To find the area aof a circle you can use the equation A = pi x radius x radius or
 * Circles and part circles are more appealing to the eye than many other shapes. Circular features in buildings, in gardens and in many other every day situations are being used with increasing popularity.**
 * Can you think of any?**
 * For a circle, the perimeter has a different name; circumference, and two formulas can be used to calculate it depending on the information given &/ or used.**
 * circumference = pi x diameter**
 * or**
 * circumference = 2 x pi x radius**

2 <span style="background-color: transparent; color: #000000; display: block; font-family: Times New Roman; font-size: 32px; text-align: left; text-decoration: none; vertical-align: auto;">A = πr <span style="background-color: transparent; color: #000000; display: block; font-family: Times New Roman; font-size: 32px; text-align: left; text-decoration: none; vertical-align: auto;">In other words, the area of a circle is pi multiplied by its radius squared.