It is known that the circumference of an isosceles triangle is 60 cm, and its waist is twice as long as its bottom. How long is the bottom of this triangle?

It is known that the circumference of an isosceles triangle is 60 cm, and its waist is twice as long as its bottom. How long is the bottom of this triangle?

If the waist length is 2 times of the bottom, the bottom is 1 times and the waist is 2 times. 60 is 2 + 2 + 1 = 5 times
Bottom edge: 60 ÷ (2 + 2 + 1) = 12 (CM)

It is known that the circumference of an isosceles triangle is 80 cm, and its waist is twice as long as its bottom. How long is the bottom of this triangle?

Waist length + waist length + bottom edge = 80,
2 * bottom edge + 2 * bottom edge + bottom edge = 80,
5 * bottom edge = 80,
Bottom edge = 80 △ 5 = 16 (CM)

6. The two sides of the isosceles triangle are 4cm and 9cm, respectively, and the perimeter is_____________ .

The length of two sides of isosceles triangle is 4cm and 9cm respectively
Only nine, nine, four
Cannot be 4,4,9 (not satisfied that the sum of two sides is greater than the third side)
So perimeter = 9 + 9 + 4 = 22cm