Question

Длина ? ширина 8 см периметр 36 см

Answer 1

P = 2 (а+b) = 2a+2b
36 = 2*8 + 2*b
2b = 36-16
2b=20
b=20/2
b=10 см - длина

проверим
2(8+10) = 36
2*18 = 36
36=36

Answer 2

Problem Analysis

We are given the width of a rectangle as 8 cm and the perimeter of the rectangle as 36 cm. We need to find the length of the rectangle.

Solution

Let's assume the length of the rectangle is 'l' cm.

The perimeter of a rectangle is given by the formula: P = 2(l + w), where P is the perimeter, l is the length, and w is the width.

Given that the width is 8 cm and the perimeter is 36 cm, we can write the equation as: 36 = 2(l + 8)

To find the length, we need to solve this equation for 'l'.

Solving the Equation

Let's solve the equation step by step:

1. Distribute the 2 on the left side of the equation: 36 = 2l + 16

2. Subtract 16 from both sides of the equation: 36 - 16 = 2l 20 = 2l

3. Divide both sides of the equation by 2 to isolate 'l': 20/2 = l 10 = l

Answer

The length of the rectangle is 10 cm.

Verification

To verify our answer, we can substitute the values of length and width into the perimeter formula and check if it equals 36 cm.

Using the formula: P = 2(l + w) P = 2(10 + 8) P = 2(18) P = 36

The perimeter is indeed 36 cm, which confirms that our answer is correct.

Conclusion

The length of the rectangle is 10 cm