What is the length of side BC of the triangle?Enter your answer in the box. ____ units

Answer:28 unitsExplanation:This is an isosceles triangle.  We can tell this by the fact that the base angles, ∠C and ∠B, are marked congruent.In an isosceles triangle, the two sides adjacent to the two congruent angles are also congruent.  This means that AC ≅ AB; it also gives us the equation2x+7 = 4x-7We do not want a variable on both sides, so we can start by subtracting 2x from each side:2x+7-2x = 4x-7-2x7 = 2x-7Add 7 to both sides to cancel it on the right:7+7 = 2x-7+714 = 2xDivide both sides by 2:14/2 = 2x/27 = xThe length of BC is 4x units; this means it is 4(7) = 28 units.