A circle with a radius of 2 cm forms a semicircle (Half of a circle). What is the area of the semicircle?

Given that the volume of a cuboid is 180 cm³ and the area of one of its rectangular face 36 cm² what is the height of the cuboid

Gemstones are commonly found in pegmatites, which are igneous rocks that are a. exceptionally mafic b. exceptionally coarse grained c. exceptionally fine grained d. extrusive, forming from lava

What evidence does the writer give to support his argument about coral reefs? a) he speaks of the activities of coral polyps. b) he describes the composition of the great barrier reef. c) he emphasizes the ways in which coral reefs are fragile. d) he points out the ways that scientists do research on the reefs.