What theorem or postulate can prove a triangle to be an isosceles?

Isosceles Triangle Theorem

two congruent  sides  OR 

two congruent sides

The angles opposite the two congruent sides of an isosceles triangle are congruent.

-12 > a

step-by-step explanation:

-11 > 1 + a

subtract 1 from each side

-11 -1> 1 -1+ a

-12 > a

step-by-step explanation:

well if you round, things become much more simple. round 5.95 to 6, 4.25 to 4, and 1.05 to 1. now, add 6+4+1 and that would equal 11. so the items together would equal to about $11.