text: ## Wednesday, July 6, 2011
  
  ### I see parallelograms everywhere
  
  Having come to terms with the area of the triangle - and realising how parallelograms unlock the secrets of so many of our basic regular shapes ....
  
  ... it's time to look at our friend the trapezium (or trapezoid if you insist).
  
  Can you turn this into a parallelogram? And how does it help work out the area?
  
  Try it out, before clicking to see more. A teacher resource is also provided at the end of the post.
  
  This is just too much fun!
  
  Here's a teacher resource for use in class - first page gives no answers, second page gives a strong helping hand. A US version using the word 'trapezoid' instead of 'trapezium' is also provided.
  Trapezium Exploration (Australia/British version)
  
  Trapezoid Exploration (US version)
  
  1. Thanks for sharing. I've never seen it this way before. I will surely use this in my classroom!
  
  2. Another clear explanation of this concept, and illustration of the formula! Love the graphics.
  
  3. I selected this to be the lead article in my online paper today: "Teach Better Math Lessons, Today": http://paper.li/Peter_Price/1309520739
  
  4. Funny thing is - I had never seen it that way either until this morning! A few days ago, a friend showed me the cutting in half trick, but we turned then manipulated the pieces into a rectangle (to get the same effect). This morning I realised we didn't need to the last step - the parallelogram was right there asking to be seen.
  
  5. I've always explained it by duplicating the trapezium and turning it around to make the parallelolellogram, but this way is more obvious. Good stuff!
  
  6. Even easier .. draw a diagonal to make two triangles! Area top triangle is 1/2 a x h, area of the bottom triangle is 1/2 b x h - add them together (student must know a little algebra) : 1/2 (a + b ) x h
  
  7. Thank you for sharing. I have a similar post here:
  
  http://mathandmultimedia.com/2010/04/09/area-tutorial-area-of-a-trapezoid/
explanation: The document is a blog post discussing the concept of turning a trapezium (or trapezoid) into a parallelogram to help understand its area. The post includes a question asking the reader to consider how turning the trapezium into a parallelogram can help in calculating its area. The post also provides teacher resources and links to related content.
distilabel_metadata.content: Evaluate the user given text extract and determine if it contains a math question and optionally and answer to this question.
  
  Output rules:
  
  1. Briefly describe the document and mention if it contains a question or a question and answer.
  2. Finalize the output with: Label: no-question,question,question-and-answer,multiple-question,multiple-question-and-answer
distilabel_metadata.role: system
distilabel_metadata.content: ## Wednesday, July 6, 2011
  
  ### I see parallelograms everywhere
  
  Having come to terms with the area of the triangle - and realising how parallelograms unlock the secrets of so many of our basic regular shapes ....
  
  ... it's time to look at our friend the trapezium (or trapezoid if you insist).
  
  Can you turn this into a parallelogram? And how does it help work out the area?
  
  Try it out, before clicking to see more. A teacher resource is also provided at the end of the post.
  
  This is just too much fun!
  
  Here's a teacher resource for use in class - first page gives no answers, second page gives a strong helping hand. A US version using the word 'trapezoid' instead of 'trapezium' is also provided.
  Trapezium Exploration (Australia/British version)
  
  Trapezoid Exploration (US version)
  
  1. Thanks for sharing. I've never seen it this way before. I will surely use this in my classroom!
  
  2. Another clear explanation of this concept, and illustration of the formula! Love the graphics.
  
  3. I selected this to be the lead article in my online paper today: "Teach Better Math Lessons, Today": http://paper.li/Peter_Price/1309520739
  
  4. Funny thing is - I had never seen it that way either until this morning! A few days ago, a friend showed me the cutting in half trick, but we turned then manipulated the pieces into a rectangle (to get the same effect). This morning I realised we didn't need to the last step - the parallelogram was right there asking to be seen.
  
  5. I've always explained it by duplicating the trapezium and turning it around to make the parallelolellogram, but this way is more obvious. Good stuff!
  
  6. Even easier .. draw a diagonal to make two triangles! Area top triangle is 1/2 a x h, area of the bottom triangle is 1/2 b x h - add them together (student must know a little algebra) : 1/2 (a + b ) x h
  
  7. Thank you for sharing. I have a similar post here:
  
  http://mathandmultimedia.com/2010/04/09/area-tutorial-area-of-a-trapezoid/
distilabel_metadata.role: user
distilabel_metadata.raw_output_q_a_detector_0: The document is a blog post discussing the concept of turning a trapezium (or trapezoid) into a parallelogram to help understand its area. The post includes a question asking the reader to consider how turning the trapezium into a parallelogram can help in calculating its area. The post also provides teacher resources and links to related content.
  
  Label: question-and-answer