Find the side lengths of each triangle. i can't figure out the formula. awnsers with work would be most . im having most trouble with 19

18. (if you needed it)

The triangle is an equilateral triangle, it has 3 congruent/equal side lengths and 3 congruent angles.

To find "z", you can set the sides equal to each other (you can just do two sides since they are all suppose to be the same lengths)

z + 5 = 4z - 4     Subtract z on both sides

5 = 3z - 4    Add 4 on both sides

9 = 3z        Divide 3 on both sides

3 = z

Plug this into one of the sides

z + 5

3 + 5 = 8       Each side is 8

[proof]

z + 5

3 + 5 = 8

4z - 4

4(3) - 4

12 - 4 = 8

3z - 1

3(3) - 1

9 - 1 = 8

19. This is an isosceles triangle, which is a triangle that has 2 congruent sides and 2 congruent angles. (The red tick marks shows that the sides are the same/equal)

Since the 2 sides are the same length, you can set them equal to each other to find "x":

2x + 6.8 = 8x + 1.4         Subtract 2x on both sides

6.8 = 6x + 1.4      Subtract 1.4 on both sides

5.4 = 6x              Divide 6 on both sides

0.9 = x

Now that you know x, you can find the sides:

2x + 6.8

2(0.9) + 6.8

1.8 + 6.8 = 8.6

8x + 1.4

8(0.9) + 1.4

7.2 + 1.4 = 8.6

The two side lengths are 8.6