Hey...i'm just doing some revision 4 some maths, and i need help with some stuff...
First Question:
Some sun bathers were surveyed when asked "Can you swim 200m non stop? 40% said yes, 30% said no, 20% said they were not sure and the rest said that they could not swim at all...
Represent this information on a Pie Graph below. Show workin' etc...
also there's one other thing...i have a ladder that's 5 m high and it's leanig against a wall, where the top of the ladder reaches just to the top, and the base of the ladder is 3 m away from the wall.
I'm trying to find out how high the wall would be...would the 3 m at the base, take off the height of the ladder, so in actual the ladder is higher than the wall or...
Would the Formula be: A= Base x Height divided by 2 of what?
yes. we know that each response in the pie chart will be represented proportionally on the pie chart, so each take up some (proportional) amount of degrees out of the 360 degrees of the circle.Originally Posted by Missy_Wattle
first you should know that "percent" means out of 100, so 40 percent is 40/100 = 0.4
also, "of" means multiply, so to find 40 percent of 360 degrees, we find
40/100 x 360 = 144
so the 40% who said yes, will take up 144 degrees of the pie
the rest are calculated similarly
we would use Pythagoras' theorem. if you drew a diagram of the setup, you'd realize that we have a right triangle with a base of 3m and a hypotenuse of 5m, and we want to find the height.
Let the two sides of the right triangle be a and b, and let the hypotenuse be c. By Pythagoras' theorem, we have:
a^2 + b^2 = c^2
here you have a and c, so plug them in and solve for b
why would we do that. that is just superfluous. we want to find the height of the wall, by Pythagoras, we get it directly. doing it as you suggested, we would have to use trig to find an angle, and then using that angle and trig again, to find the height. that's just too much work here.
just plug in the x-values and solve for y. for example, in the x = 0 column, the y-value under it is given by: y = 2x + 3, so when x = 0, y = 2(0) + 3 = 3. so y = 3 is the corresponding y-value. fill out the rest of the table
for the second question, use your table to plot the points you got and draw the line. then look for 11 on the y-axis. draw a horizontal broken line from the 11 to the line you graphed, and then a vertical broken line down to the x-axis. the line will cut the x-axis at the required x-value
your barn is very small, how many animals you got in there? the scale is 1:100, that means for every 1 cm on the diagram, we have 100 cm in actuality. so the barn is 10(100)cm by 5(100)cm = 1000cm by 500cm = 10 meters by 5 meters, ok, so that's not THAT small, but it's still small
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