ANSWER my question IF YOU WANT TO HAVE BRANIEST

In a certain triangle, two of the sides have measures of 13 and 20. If the triangle is isosceles, then which of the following could be the measure of the third side?
1) 7
2) 33
3) 40
4) 13

4)13

Step-by-step explanation:

In geometry, an isosceles triangle is a triangle that has two sides of equal length. Sometimes it is specified as having exactly two sides of equal length, and sometimes as having at least two sides of equal length, the latter version thus including the equilateral triangle as a special case.

answer: -1

step-by-step explanation:

12

step-by-step explanation:

a triangle's   full angle is 180 degrees so 180 - 156 = 24. 24/2=12