Question

Henry wants to laminate the tabletop in his study room. The tabletop is the shape of an isosceles trapezoid shown here. If laminating costs $4 per square foot, what is the total cost to laminate the tabletop? A trapezoid with a height of 3 feet and bases of 6 feet and 10 feet is shown. $24 $72 $84 $96

Answer 1

$96 

Area
(6+10)/2 x 3
=24 squared feet 

24 x $4 = $96

Answer 2

First we have to find the area of the trapezoid. 

Let's separate the trapezoid into 3 shapes. Two triangles, and 1 rectangle.
(I included an image of an isosceles trapezoid for reference)

First let's find the area of the triangles. 
We'll use this equation.
a = area
b = base
h = height
a = b · h · 0.5
a = b · 3 · 0.5

We need to find the base of the triangle. 
To do this, we'll subtract 6 from 10, which equals 4. 4/2= 2 which is the base of the left and right triangle. Let me know if you're confused by that!!

a = 2 · 3 · 0.5
a = 6 · 0.5
a = 3
The area of both triangles is 3.

Now we need to find the area of the rectangle. 
We'll use this equation.
a = b · h
a = 6 · 3
a = 18

So the rectangle's area is 18, and both triangle's area is 3.
18 + 3 + 3 = 24

Now we need to find the cost. 
24 · 4 = 96

The answer is $96. 

Hope this helps! :)