Answer:
a) m∠BPD = 120°
b) m∠BC + m∠AD = 120°
Explanation:
a) To solve for question a, we make use of a theorem called the intersecting chord theorem. This states that:
The measure of the angle formed by two chords that intersect inside a circle is the average of the measures of the intercepted arcs.
The Interior angle =( The larger exterior arc + The smaller exterior arcs) ÷ 2
The larger exterior arc (m∠BD) = 170°
The small exterior arc (m∠CA) = 70°
m∠BPD = m∠BD + m∠CA/2
m∠BPD = 170° + 70°/2
= 240°/2
= 120°
b) We are to find m∠BC + m∠AD
The sum of exterior angles in a circle = 360°
360° = m∠BD + m∠CA + m∠BC + m∠AD
360° = 170° + 70° + m∠BC + m∠AD
360° = 240 + m∠BC + m∠AD
360 - 240° = m∠BC + m∠AD
Thererefore,
m∠BC + m∠AD = 120°