Examples with solutions for Area of a Rectangle: A shape consisting of several shapes (requiring the same formula)

Exercise #1

Look at the rectangle below.

888222AAABBBCCCDDDEEEFFF

What is the area of the rectangle ABCD?

Video Solution

Step-by-Step Solution

Given that in a rectangle every pair of opposite sides are equal, we can claim that:

AB=DC=8 AB=DC=8

and also:

BE=EC=2 BE=EC=2

In other words, BC equals 4

Now we can find the area of the rectangle by multiplying the length by the width:

AB×BC=8×4=32 AB\times BC=8\times4=32

Answer

32 cm²

Exercise #2

Look at the given rectangle made of two squares below:

555AAABBBCCCDDDEEEFFF

What is its area?

Video Solution

Step-by-Step Solution

In a square all sides are equal, therefore we know that:

AB=BC=CD=DE=EF=FA=5 AB=BC=CD=DE=EF=FA=5

The area of the rectangle can be found in two ways:

  1. Find one of the sides (for example AC)

    AC=AB+BC AC=AB+BC

    AC=5+5=10 AC=5+5=10

    and multiply it by one of the adjacent sides to it (CD/FA, which we already verified is equal to 5)

    5×10=50 5\times10=50

  2. Find the area of the two squares and add them.

    The area of square BCDE is equal to the multiplication of two adjacent sides, both equal to 5.

    5×5=25 5\times5=25

    Square BCDE is equal to square ABFE, because their sides are equal and they are congruent.

    Therefore, the sum of the two squares is equal to:

    25+25=50 25+25=50

Answer

50

Exercise #3

What is the area of the shape below?

141414222111333

Video Solution

Step-by-Step Solution

First, let's draw an imaginary line so that we get a shape containing one large rectangle and one small rectangle.

Then we can calculate the area of the large rectangle:

14×2=28 14\times2=28

Next we will calculate the area of the small rectangle:

1×3=3 1\times3=3

Finally, we combine the two areas to get the answer:
28+3=31 28+3=31

Answer

31 cm²