the measures of the lengths of two sides of an isosceles triangle are x and 2x+1. Then, the perimeter of the triangle is
(A) 4x
(B) 4x+1
(C) 5x+1
(D) 5x+2
(E) None of the above

Question

anonymous · Answer

An isoceles triangle has atleast two sides equal. So the perimeter is either:
x+x+2x+1 = 4x+1 or
x+2x+1+2x+1 = 5x+2

So the answer is B and D

anonymous · Answer

It would actually need to be just D; by the triangle inequality (the lengths of any two sides must be greater than the length of the third side) the longer, and therefore 'double' side would be of length 2x + 1. Thus, the answer would be 2 (2x + 1) + x = 5x + 2.

myininaya · Answer

2x+1>x for any x>0
so wouldn't it be x+x+2x+1=4x+1