Answer:
11.34cm
Step-by-step explanation:
The mnemonic SOH CAH TOA tells you the relationship between the side opposite an angle and the side adjacent:
... Tan = Opposite/Adjacent
That is, for your triangle, ...
... tan(80°) = QR/(2 cm)
Multiplying this equation by 2 cm gives ...
... tan(80°)·(2 cm) = QR = 5.67·2 cm = 11.34 cm
