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An isosceles triangle has a perimeter of 28cm and sides of integer length.
How many different such triangles can be made?

Respuesta :

Answer:

over 18716271717161626cm

To solve this question, we have to:

  • Understand the concept of an isosceles triangle.
  • Understand the perimeter concept.
  • Understand the constraint needed to represent a triangle.

Doing this, we get that: 6 different such triangles can be made.

Isosceles triangle:

In an isosceles triangle, two sides have the same measure. An example is given by the picture at the end of this answer.

Perimeter:  

The perimeter of a polygon, in this case a triangle, is the sum of all it's sides.

Constraint:

The sum of the lengths of the two smaller sides of a triangle has to be greater than the length of the greater side.

This triangle:

  • Perimeter of 28.
  • Two sides of x.
  • One side y

Thus, the perimeter is:

[tex]P = 2x + y = 28[/tex]

Now, for the values of x, we find if the values of y generate a triangle, respecting the constraint.

x = 1

[tex]2 + y = 28 \rigtharrow y = 26[/tex]

1 + 1 < 26, thus, the constraint is not respected.

x = 2

[tex]4 + y = 28 \rightarrow y = 24[/tex]

2 + 2 < 24, thus, the constraint is not respected.

x = 3

[tex]6 + y = 28 \rightarrow y = 22[/tex]

3 + 3 < 22, thus, the constraint is not respected.

x = 4

[tex]8 + y = 28 \rightarrow y = 20[/tex]

4 + 4 < 20, thus, the constraint is not respected.

x = 5

[tex]10 + y = 28 \rightarrow y = 18[/tex]

5 + 5 < 18, thus, the constraint is not respected.

x = 6

[tex]12 + y = 28 \rightarrow y = 16[/tex]

6 + 6 < 16, thus, the constraint is not respected.

x = 7

[tex]14 + y = 28 \rightarrow y = 14[/tex]

7 + 7 = 14, thus, the constraint is not respected.

x = 8

[tex]16 + y = 28 \rightarrow y = 12[/tex]

8 + 8 > 12, thus, the constraint is respected, and this is the first possible triangle.

x = 9

[tex]18 + y = 28 \rightarrow y = 10[/tex]

9 + 9 > 10, thus, the constraint is respected, and this is the second possible triangle.

x = 10

[tex]20 + y = 28 \rightarrow y = 8[/tex]

8 + 10 > 10, the constraint is respected, and this is the third possible triangle.

x = 11

[tex]22 + y = 28 \rightarrow y = 6[/tex]

11 + 6 > 11, the constraint is respected, and this is the fourth possible triangle.

x = 12

[tex]24 + y = 28 \rightarrow y = 4[/tex]

4 + 12 > 12, the constraint is respected, and this is the fifth possible triangle.

x = 13

[tex]26 + y = 28 \rightarrow y = 2[/tex]

13 + 2 > 13, the constraint is respected, and this is the sixth possible triangle.

x = 14

[tex]28 + y = 28 \rightarrow y = 0[/tex]

Cannot have a triangle with a side of 0, so this is not possible.

After the tests, we have that 6 different such triangles can be made.

A similar question is given at https://brainly.com/question/6139098

Ver imagen joaobezerra