Answer:
m∠C = 102°
Step-by-step explanation:
This diagram is a Quadrilateral inscribed in a circle
The first step is to determine what m∠B
is
The sum of opposite angles in an inscribed quadrilateral is equal to 180°
m∠D + m∠B = 180°
m∠B = 180° - m∠D
m∠B = 180° - 80°
m∠B = 100°
Second step is we proceed to determine the exterior angles of the circle
m∠ADC = 2 × m∠B
m∠ADC = 2 × 100°
m∠ADC = 200°
m∠ADC = m∠CD + m∠AD
m∠AD = m∠ADC - m∠CD
m∠AD = 200° - 116°
m∠AD = 84°
The third step is to determine m∠BAD
m∠BAD = m∠AD + m∠AB
m∠BAD = 84° + 120°
m∠BAD = 204°
The final step Is to determine what m∠C is
It is important to note that:
m∠BAD is Opposite m∠C
Hence
m∠C = 1/2 × m∠BAD
m∠C = 1/2 × 204
m∠C = 102°
