Answer:
The measure of ∠QML is 90°
The measure of ∠PMN is 117°
Step-by-step explanation:
In circle O:
- MQ is a diameter
- LN is a tangent to circle O at point M
- PM and RQ are secants
- m∠PMO is 27°
- m∠MQR is 42
∵ MQ is a diameter of circle O
∵ LN is a tangent to circle O at point M
- A diameter is perpendicular to a tangent at the point of
contact between them (one of end-point of the diameter)
∴ QM ⊥ LN at point M
∴ m∠QML = m∠QMN = 90°
The measure of ∠QML is 90°
∵ m∠PMN = m∠PMO + m∠QMN
∵ m∠PMO = 27° ⇒ given
∵ m∠QMN = 90° ⇒ proved
∴ m∠PMN = 27 + 90
∴ m∠PMN = 117°
The measure of ∠PMN is 117°
