Slide 1

Slide 2 Perimeter of the Lovely El What is the perimeter of this shape? (all the angles are 90 degrees ) Slide 3 Perimeter of the Lovely El Perimeter: the distance around an area. Slide 4 It doesnt have to be a regular shape, either. Slide 5 The perimeter around Parkland College is 1.45 miles Slide 6 Peri means around. 8 cm 7 cm 4 cm 6 cm 2 cm 1 cm perinatal means happening around the birth time perimeter means measuring around a shape. Slide 7 8 units 7 units 6 units 2 units 1 unit The units have to be the same thing. If one side is measured in centimeters and the other in inches or feet or miles, adding the numbers together would just give you a number, not the answer to a question. (Its same to same in the addition game!) 4 units Slide 8 Perimeter: Add the distances of each side. 8 units 7 units 4 units 6 units 2 units 1 unit Notice that youre measuring a distance, so your starting point is 0, not one. Youre counting the spaces the distance not the lines used to mark each unit. Slide 9 What if we dont know all the distances? 6 units 3 units 0 We dont have to measure them. We can still figure things out, because as long as those angles are 90 degree perfect corners, we can use what we know about Parts and Wholes and just watch 4 units 2 units Slide 10 What if we dont know all the distances? 6 units 3 units 0 4 units 2 units Trace these lines with your finger. Theyre parallel going *exactly* the same vertical (up and down) direction. Theyd never meet even if they went on forever to infinity. Slide 11 What if we dont know all the distances? 6 units 3 units 0 4 units 2 units Which distance is the whole way from top to bottom? Im the whole! Me! Slide 12 What if we dont know all the distances? 6 units 3 units 0 4 units 2 units The part were looking for where is it? ? Im the missing *part* Im the whole! Me! Slide 13 What if we dont know all the distances? 6 units 3 units 0 4 units 2 units The part you already know is where? Im the missing *part* Im the part you know! Im the whole! Me! Slide 14 What if we dont know all the distances? 6 units 3 units 0 4 units 2 units To find a part. Subtract the part from the whole. Whole minus part = part Im the missing *part* Im the part you know! Im the whole! Me! Slide 15 One more time 6 units 3 units 0 4 units 2 units First trace the lines to find the ones going the same direction. Im the missing *part* Im the part you know! Im the whole! Me! Slide 16 One more time 6 units 3 units 0 4 units 2 units First trace the lines to find the ones going the same direction. Next, figure out which are the parts, and which is the whole. Im the missing *part* Im the part you know! Im the whole! Me! Slide 17 One more time 6 units 3 units 0 4 units 2 units First trace the lines to find the ones going the same direction. Next, figure out which are the parts, and which is the whole. Subtract to find a missing part; add to find a whole. Im the missing *part* Im the part you know! Im the whole! Me! Slide 18 You might want to backtrack 6 units 3 units 0 4 units 2 units Go through these steps then figure out the other missing side! Im the missing *part* Im the part you know! Im the whole! Me! ???? units Slide 19 Some other resources http://www.bbc.co.uk/bitesize/ks3/maths/me asures/ http://www.bbc.co.uk/bitesize/ks3/maths/me asures/ Make all the practice worksheets you want http://www.worksheetworks.com/math/geom etry/measuring-figures/perimeter-area.html http://www.worksheetworks.com/math/geom etry/measuring-figures/perimeter-area.html