If angle between two radii of a circle is $130^\circ$, then the angle between the tangents at the ends of the radii is:
$90^\circ$
$50^\circ$
$70^\circ$
$40^\circ$
Step-by-Step Solution
Key Concept: The angle between the two tangents and the angle subtended by the radii at the center are supplementary ($180^\circ$).
Stepwise Solution:
$\text{Angle between tangents} + 130^\circ = 180^\circ$. [0.5 Mark]
$\text{Angle between tangents} = 180^\circ - 130^\circ = 50^\circ$. [0.5 Mark]
Marking Scheme:
• Stating supplementary relationship: 0.5 Mark
• Calculating $180^\circ - 130^\circ = 50^\circ$: 0.5 Mark
Correct Answer: $50^\circ$