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Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,Do Now 10/12/09,Copy HW in your planner.,Text p.165,#28-34 evens,#46-50 evens,Text p.171-172,#16-38 even,In your journal,consider the following.On a bright sunny day,how can you determine the height of a tall object(i.e.flagpole)without physically measuring the object?,Objective,SWBAT find ratios and write and solve proportions,SWBAT solve proportions using cross products,RATIO-,uses division to compare two quantities,a to b,a:b,a,b,You can write ratios three different ways:,Section 3.5“Write Ratios and Proportions,Try It Out,SOLUTION,VOLLEYBALL,A volleyball team plays,14,home matches and,10,away,matches,.,a.,Find the ratio of home matches to away matches.,=,7,5,a.,home matches,away matches,14,10,=,b.,Find the ratio of home matches to all matches.,b.,home matches,all matches,14,14+10,=,=,14,24,=,7,12,PROPORTION-,an equation that states that two ratios are equivalent.,Try It Out,11,6,x,30,=,Write original proportion.,Multiply each side by,30.,330,6,=,x,Simplify.,55,=,x,Divide.,11,6,x,30,=,30,30,x,30,Solve the proportion,11,6,=,.,Proportion Cross Products Property,A,CROSS PRODUCT,is the product of the numerator of one ratio and the denominator of the other ratio in a proportion.,If ,then,Section 3.6“Solving Proportions Using Cross Products,Write original proportion.,8 15=,x,6,Solve the proportion,=,8,x,6,15,Cross products property,Simplify.,120=6,x,Divide each side by,6,.,20,=,x,=,8,x,6,15,3,x,=,2,x,6,Cross products property,3(,x,6)=,2,x,3,x,18=2,x,Distributive property,Subtract,3,x,from each side.,18=,x,Solve the proportion,3,x,=,2,x,6,Write original proportion.,SCALE,-,the SCALE of a drawing,map,or model relates the dimensions of the drawing,map,or model to the actual dimensions.,Write and solve a proportion to find the distance,d,between Cleveland and Cincinnati if the distance on the map is about 4.2 centimeters.,=,4.2,d,1,centimeters,85,kilometers,Cross products property,d,=357,Simplify.,1,d,=85 4.2,The ship model kits sold at a hobby store have a scale of,1 ft:600 ft.,A completed model of the Queen Elizabeth II is,1.6,feet long.Estimate the actual length of the Queen Elizabeth II.,Write and solve a proportion to find the length,g,of the Queen Elizabeth,II,.,=,1.6,g,1,600,Cross products property,g,=960,Simplify.,1,g,=600,1.6,SOLUTION,The actual length of the Queen Elizabeth,II,is about,960,feet.,Indirect Measurements,You measure the shadow of a telephone pole to be 24 ft.The shadow of a 5ft-tree is 4 ft.How tall is the telephone pole?,S,H,s,h,Homework,Text p.165,#28-34 evens,#46-50 evens,Text p.171-172,#16-38 even,24,Homework,Real-Life Applications Worksheet,1),2),3),4),b.about 1 inches,c.the city locations on the maps are approximations,
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