Answer:
The correct answer will be- both observation and experimentation
Step-by-step explanation:
The determination of length and weight of the pine trees of the forest can be determined by the scientific method.
The observation must be done to measure the length and weight of the trees using the instruments whereas the calculation of the measurement must be done through a systematic approach to calculating the average.
Both observation and experimentation are steps of the scientific method which can lead to the answer therefore, both observation and experimentation are correct.