How do you find the length of a missing side when you already have the other two sides and you need the last side?

Suppose there are 10 five and six-year-old attending a birthday party. when a 30 year old mother walks into the room with an infant in her arms, what happens to the mean age in the room? what happens to the standard deviation of ages in the room? a. the mean and standard deviation of both change. b. the meaning will change, but the standard deviation will stay approximately the same. c. i mean will stay approximately the same, but the standard deviation will change. d. the mean and standard deviation will both stay approximately the same.

In triangle △abc, ∠abc=90°, bh is an altitude. find the missing lengths. ah=4 and hc=1, find bh.

45% of the trees in a park are apple trees. there are 27 apple trees in the park. how many trees are in the park in all?