An isosceles triangle has a base 10 units long. If the congruent sides have whole number measures, what is the least possible length of the sides?

A. 5
B. 6
C. 17
D. 21

I know the answer is B, but I don't know why. Please explain, thanks!

Question

An isosceles triangle has a base 10 units long. If the congruent sides have whole number measures, what is the least possible length of the sides?

A. 5
B. 6
C. 17
D. 21

I know the answer is B, but I don't know why. Please explain, thanks!

anonymous · Answer

x+x>10
2x>10
x>5

anonymous · Answer

for it to be a triangle, the sum of the 2 shortest sides must be greater than the longest side

anonymous · Answer

none of the other choices form a triangle

anonymous · Answer

5+5>10? no
6+6>10? yes
10+17>17? no
10+21>21? no

anonymous · Answer

well the last 2 actually do form a triangle, what am i talking about lol.  but the question is the least possible dimensions

anonymous · Answer

Oh okay, I see now. Thanks!