Question

Периметр треугольника MNC равен 66 см. сторона NC равна 16 см, и она меньше стороны MC на 15см. Найдите длину стороны MN..... Напишите решение

Answer 1

16+15=31
31+16=47
66-47=19
ответ 19

Answer 2

Вот, надеюсь, что всё понятно:)

Answer 3

Problem Analysis

We are given that the perimeter of triangle MNC is 66 cm. We are also given that side NC is 16 cm long and is 15 cm shorter than side MC. We need to find the length of side MN.

Solution

Let's assume that the length of side MC is x cm. Since side NC is 15 cm shorter than side MC, the length of side NC can be expressed as (x - 15) cm.

The perimeter of a triangle is the sum of the lengths of its sides. Therefore, we can write the equation:

MC + NC + MN = 66

Substituting the given values, we have:

x + (x - 15) + MN = 66

Simplifying the equation, we get:

2x - 15 + MN = 66

Rearranging the equation, we have:

MN = 66 - 2x + 15

MN = 81 - 2x

Now, we need to find the value of x in order to calculate the length of side MN.

To find the value of x, we can use the fact that the sum of the lengths of any two sides of a triangle must be greater than the length of the third side. In this case, we have:

MC + NC > MN x + (x - 15) > MN

Simplifying the inequality, we get:

2x - 15 > MN

Since the length of side MN cannot be negative, we can set the inequality to be greater than or equal to zero:

2x - 15 >= 0

Solving the inequality, we have:

2x >= 15 x >= 7.5

Therefore, the length of side MC must be greater than or equal to 7.5 cm.

Now, let's substitute the value of x into the equation MN = 81 - 2x to find the length of side MN:

MN = 81 - 2(7.5) MN = 81 - 15 MN = 66 cm

Therefore, the length of side MN is 66 cm.

Answer

The length of side MN is 66 cm.