Answer:
12
Step-by-step explanation:
Hi!
We're given that the perimeter is 76. A triangle's perimeter is given by the sum of all of the sides. So, we'll find the lengths of the sides of the triangle and add them.
This is an isosceles triangle. The legs of an isosceles triangle are equal. In this problem, we're given the length of one leg: 3x-4. That means that the length of the other leg is also 3x-4. Now, the last side of the triangle is x ("base is x).
2(3x-4) + x = 76
6x-8+x=76
7x-8=76
7x=84
x=12
Let's check our answer.
3(12) - 4 =36-4 = 32
32 times 2 = 64 +12 =76
Correct!