Posted by Brad Paul on October 30, 2002 at 12:25:01:
In Reply to: Re: Area help needed posted by Jim on October 30, 2002 at 11:59:17:
: The parralel sides of the trapezium are:
: 19.3 and 9
: So 8.6*(19.3+9) should = 243.38
: I hope the text book is wrong, doubt it though...anyone care to show what they get?
Look at the equation I gave you in my 1). It gives:
8.6*(19.3+9)/2=121.69
To derive this equation (which I did because I always forget this
stuff) is to draw a trapezium and label the height h and the top and
bottom lengths say t, and b. Now break your figure into two triangles
and one rectangle. Find the area of all three then simplify the sum.