# Area of triangles

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This student was able to find dozens of triangles with an area of 4 square units using patterns on the geo-board. There are many activities you can try to consolidate your knowledge of area. Try IXL Maths practise, compare area and perimeter of two figures or Mathletics and Rainforest maths. Maths 300 is also an excellent resource for learning about the area of triangles. Click on the green triangle on the desktop of the computers in the pod or the lab to connect to Maths 300 activities.

Using grid paper, create triangles of fixed base and height length (for example, 5cm base and 4cm perpendicular height). Cut out these shapes and try to form squares or rectangles with them, so you can easily calculate the area. You will find that the height of the rectangle formed with the pieces of the triangle is half the height of the original triangle. So, the area of a triangle is equal to half x base x height.

Go to Technomaths to complete the student survey about your Maths learning in Semester 1. I have decided to use another blog for maths posts to keep current work closer to the top of the page. So make sure you bookmark the Technomaths website for future use.

# Perimeter and Area

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Year 6/7 classes have enjoyed having a student teacher, Zac Doherty, over the past couple of weeks. Zac is a past student doing his Graduate Diploma of Education teaching practicum rounds. Students have learnt about measuring length and perimeter and now we are starting to look at area of squares, rectangles, triangles and composite shapes.

Here  is a link to the Learning Federation interactive “Area of triangles“, which shows why we use the formula “the area of a triangle is equal to half the base multiplied by the height”.

This HOTmaths activity is also a great way to learn about area and perimeter. The HOTmaths site has several free activities and links to investigations (in pdf format) suitable for middle years students.

This a simple site for learning more about area and perimeter. Maths Playground has a good explanation of perimeter versus area and some interactive activities for students to learn more.

# Pizza maths

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This week in Maths we are continuing our study of area, looking at the area of circles. Earlier in the year we measured the diameter and circumference of many different-sized circles and found the relationship between those values. We found that the ratio between the diameter and the circumference of a circle is a little more than 3. Archimedes, the famous Greek mathematician, accurately determined the value of ‘pi’ over 200 BC. We use pi = 3.14 or 22/7 as an estimate for calculations, as the real value is a never-ending (irrational) number. This value can be used to calculate the area of a circle. Students calculated the area of small, medium and large pizzas and then we used the prices of different pizzas from our local restaurant to calculate the value of different sizes and toppings.