If two circles are concentric then
a) they will have the same area.
b) they will have the same center.
c) they will have the same radius length, but different diameter length.
d) they will have the same diameter length, but different radius length.

In triangle abc, the length of side ab is 12 cm, the length of side bc is 5 cm, and the length of side ca is 9 cm. find the measure of angle a using the law of cosines.

Rewrite the following without an exponent. (5/8)-1

Organisms that live in the alpine and taiga biomes have developed unique adaptations that aid in their survival. the douglas-fir is a conifer tree that grows in the taiga biome. it has an average height of about 70 feet, and its wood is an important source of lumber.