Construct an equilateral triangle, given its side and justify the construction.

Construct an equilateral triangle of side 5.5 cm

An equilateral triangle of side 9 cm.

Construct an equilateral triangle with perimeter 14.5 cm.

Construct an angle of 90^@ at the initial point of a given ray and justify the construction.

Construct an angle of 45^@ at the initial point of a given ray and justify the construction.