Question: What is the area covered by three squares?

Answer:

You can use simultaneous equations to solve it, but there is also an alternative one.

All of them are squares, but have different lengths. Let’s label a, b, and c as shown.

Obviously, a+b+c is equal to 24 m as given. Thus, the length of the red part must be 24 m in the same sense.

Then, look at the blue part. This length will be 3 times one side of the largest square; and it is equal to 6+a+b+c+3.

Remember that a+b+c=24, so the length of the blue line should be 6+24+3=33.

Therefore, the the length of one side of the largest square is b=33/3=11.

Now, we can derive a=11-6=5; and c=11-3=8.

Each area of the square is: 5×5=25, 11×11=121, and 8×8=64.

The total area is 25+121+64=210 m^2.