The circumference of an isosceles triangle is 30cm, and the length of one side is 6cm______ ．

The circumference of an isosceles triangle is 30cm, and the length of one side is 6cm______ ．

∵ the perimeter of isosceles triangle is 30cm, and one side of triangle is 6cm long. ∵ if 6cm is the bottom side length, then the waist length is: (30-6) △ 2 = 12 (CM), ∵ 6cm, 12cm, 12cm can form triangle. ∵ at this time, the other sides are 12cm, 12cm; if 6cm is the waist length, then the bottom side length is: 30-6-6 = 18 (CM)

If the four corners of a rectangle with a width of 3cm and a length of 5cm are cut out of the square with a side length of 1cm, the perimeter of the enclosed figure will be smaller
(bigger or smaller, same)

The perimeter should be the same

As shown in the figure, there is a rectangular sheet of iron with a width of 16 cm. Cut out the square with a side length of 4 cm on its four corners. At this time, the perimeter of the new figure is 80 cm
Cm, how many square centimeters can you find out the area of the original rectangle?

Cut off the four corners and keep the perimeter unchanged,
Length = 80 △ 2-16 = 40-16 = 24 cm;
Original area = 24 × 16 = 384 square centimeter;
If you don't understand this question, you can ask,

Cut out a rectangle with a length of 12 cm and a width of 5 cm at one corner of a square with a side length of 22 cm. What is the circumference of the remaining paper

22✘4=88