a Each of the smaller rectangles are a product of their horizontal and vertical side.
B
b Each of the smaller rectangles are a product of their horizontal and vertical side.
A
a 420 units^2
B
b 80 units^2
Practice makes perfect
a Examining the diagram, we see that the lower left small rectangle has a vertical and a horizontal side of 10 and 8. This means it has an area of 10* 8 units^2.
The upper left rectangle has an area of 40 units^2. Since the horizontal side is 8 units, the vertical side must be 5 units in order to make an area of 40 units^2.
When we know the vertical side of the upper right rectangle, we can identify its horizontal side and also the area of the lower right rectangle.
Let's perform the multiplications.
Finally, we will add the areas of the four rectangles to calculate the total area.
40+100+80+200=420 units^2
b Like in Part A, we can identify the vertical sides by factoring the area expressions of the lower left and upper right rectangles.
Now we can identify the product of the upper left and lower right rectangle.
Let's perform the multiplications.
Finally, we will add the areas of the four rectangles to calculate the total area.
8+24+12+36=80 units^2
