geometry
posted by Billy .
An isosceles triangle has a base of 9.8 units long. If the congruent side lengths have measures to the first decimal place, what is the shortest possible length of the sides.

a + c > b,
a + c > 9.8, a  c.
Substitute a for c:
a + a > 9.8,
2a > 9.8,
a > 4.9,
a = c = 5.1.