Answer:
IS = 2 cm , ∠ FYI = 90° , ∠ HSF = 45°
Step-by-step explanation:
(a)
In a square
• All sides are congruent (equal ), then
IS = FI = 2 cm
(b)
• diagonals are perpendicular bisectors of each other , then
∠ FYI = 90°
(c)
• All angles are right
• diagonals bisect the angles , then
∠ HSF = 45°