someone please help me answer this!!

Answer:
a = 8mm is the answer
Step-by-step explanation:
a = ?
b = 6mm
c = 10mm
By using the Pythagoras theorem,
a² + b² = c²
a² + 6² = 10²
a² + 36 = 100
a² = 100 - 36
a² = 64
a = 8
∴ a = 8mm is the length of the missing leg