Answer:
triangle 1, triangle 3,
Step-by-step explanation:
Triangle 1= 
Triangle 2= is wrong
Triangle 3= 
Triangle 4= is wrong.
The best measure of center tendency for this set of data would be the median. It is the best measurement because the data set has an outlier. The outlier is the 30. So to find the median we first order the data set and then find out if the set is an even or odd set. This set is even so we just chose the middle number. If the set was even, we would add the two center number and divide them by 2.
3, 3, 4, 4, 4, 5, 5, 5, 30
The center tendency = 4
A theorem is defined as an existing fact that was proved to be correct through experimentation or mathematical reasoning. In this case, we can say that a theorem can be proven by geometric proof as it is required for people to consider it as a fact. Answer is true.