Use 20 squares with 1cm sides to form a rectangle. If the perimeter of the rectangle is the shortest, then one long side of the rectangle should be () cm

Use 20 squares with 1cm sides to form a rectangle. If the perimeter of the rectangle is the shortest, then one long side of the rectangle should be () cm

Use 20 squares with 1cm sides to form a rectangle. If the perimeter of the rectangle is the shortest, then one long side of the rectangle should be (5) cm

If the width of a rectangle is x cm and the length is 1 cm more than twice the width, the perimeter of the rectangle is______ Cm

∵ the width of a rectangle is x cm, and the length is 1 cm more than 2 times of the width, ∵ the length of a rectangle is (2x + 1) cm, ∵ the circumference of a rectangle = 2 (x + 2x + 1) = 2x + 4x + 2 = 6x + 2 (cm). So the answer is (6x + 2)

The first time is 1, the second time is 3, the third time is 6, the fourth time is 10, and the N times is how many cm is the circumference of the figure

According to the law of operation, it can be found that 5 is 15, 6 is 21, 7 is 28
N times is (1 + n) * n / 2
Then the perimeter of the graph is [1 + (1 + n) * n / 2] * 2 = n * (n + 1) + 2