Geometry math question no guessing and show work you

two sides are 3 and 6

since triangle is isosceles , the third side can be either 3 or 6

In a triangle , sum of two sides > third side

checking for third side=3 we have {3,3,6}

3+3>6, 6>6 ( false)

checking for third side =6 , we have (3,6,6)

3+6>6 , 9>6 ( true)

6+6>3, 12>3 (true)

so the third side must be 6

Option C. 6 is the correct answer