Answer:
The length of AC is 10 units
Step-by-step explanation:
In the given circle O
∵ AOCB is a rectangle
∵ OB and AC are the diagonals of the rectangle AOCB
∵ Diagonals of the rectangle are equal in lengths
→ That means OB and AC are equal in lengths
∴ OB = AC
∵ O is the center of the circle
∵ B is a point on the circle
∴ OB is a radius of the circle O
∵ The radius of the circle is 10 units
∴ OB = 10 units
∵ OB = AC
∴ AC = 10 units
∴ The length of AC is 10 units