Question 1176072
A trapezoidal room is to be tiled. The bases are 90 feet and 100 feet, and the
height is 30 feet. What is the cost if the tile costs $1.10 per square foot?

{{{matrix(1,3,

Area, ""="", (matrix(1,2,average,base))*height))}}}
<pre>
First we average the bases by adding them and taking half

adding the bases gives 90+100 = 190
Dividing by 2 gives 95 for the average base

So we plug in the formula:

{{{matrix(1,7,

Area, ""="", 95*30, ""="", 2850, "sq.","ft.")}}}

Then we multiply by $1.10 per sq. ft.

{{{matrix(1,5,

Cost, ""="", "$1.10"*2850, ""="", "$3135.00")}}}

Edwin</pre>