Sides opposite to equal angles of a triangle are . (Equal/Unequal)

Angle opposite to equal sides of a triangle are _____.

In an equilateral triangle all angles are _____.

In a$ABC$, if $\angle A=\angle C,$ then $AB=$_____.

If altitudes $CE$ and $BF$ of a triangle $ABC$ are equal, then $AB=$_____.

In an isosceles triangle $ABC$ with $AB=AC,$ if$BD$ and $CE$ are its altitudes, then $BD$is _____ to $CE$.

In right triangles $ABC$ and $DEF,$ if hypotenuse $AB=EF$and side $AC=DE$, then $\Delta ABC\cong \Delta$_____.