Answer:
so $21+45%=30.45. meaning that pair of boots cost 30.45 so two pairs of boots would cost $60.90
Sorry man I don't know if im write but try 28.78
Answer:

Step-by-step explanation:
√(-100)
Use the imaginary number rule 
√(-1) × √(100)
i × √(10²)
i × 10
= 10i
Since all three sides are different lengths and angles, that triangle would be considered an Isosceles triangle.