Possible Clues:

• Spokes of a circle
• They go straight in a circle
• Bones found in a brief excavation in US state
• Shadows on an equatorial sundial, say
• They're parallel to 105-Down
• Over two speaking of attack, more than one spoke
• Lines from the centre to the circumference of a circle
• Euclid's arms?
• Two make the diameter
• Minute hands, say