How many rectangles ( if that is the square included) are there in the figure below?
Answer
There are five vertical lines and four horizontal lines in this figure.
The answer becomes the number of ways which is chosen two lines out of five and two line out of four.
It is (5 × 4) / (2 × 1) = 10 ways and (4 × 3) / (2 × 1) = 6 ways, in total, 10 ways × 6 ways = 60 ways.
Therefore, the number of rectangle is 60.
60
Solution
Rectangle is a figure that is surrounded by two horizontal lines and two vertical lines.
There are five vertical lines and four horizontal lines in this figure.
The answer becomes the number of ways which is chosen two lines out of five and two line out of four.
It is (5 × 4) / (2 × 1) = 10 ways and (4 × 3) / (2 × 1) = 6 ways, in total, 10 ways × 6 ways = 60 ways.
Therefore, the number of rectangle is 60.
