Starter 1cm 2cm 2cm 1cm 1cm 2cm The area of a rectangle is …………………………… Copyright 2011 Humancoaching.net We are learning to: • Understand how to work out the area of a triangle • Know and understand the formula for the area. Key idea: We can think of every triangle having it’s own rectangle Key words: base, height, area. Copyright 2011 Humancoaching.net TheCopyright area2011 of these rectangles is … Humancoaching.net Off cuts Cut out Copyright 2011 Humancoaching.net Copyright 2011 Humancoaching.net What do you notice? Might it always be true? Copyright 2011 Humancoaching.net Copyright 2011 Humancoaching.net 4. What are the areas of the four triangles 5. How do you work out the area of a triangle e.g this one below. 4. 6. So the formula (or method is) ? Copyright 2011 Humancoaching.net c b a d For each rectangle work out it’s area. a = _____ b = _____ c = ______ d = ______ Copyright 2011 How many of the triangles fit into each rectangle? ________ Humancoaching.net Extension 1 Copyright 2011 Extension 2 Copyright 2011