Find the surface area of the regular pyramid.

Polygons efgh and e′f′g′h′ are shown on the coordinate grid: what set of transformations is performed on efgh to form e′f′g′h′? a. a translation 1 unit to the left followed by a 90-degree counterclockwise rotation about the origin b. a translation 1 unit to the right followed by a 90-degree counterclockwise rotation about the origin c. a 90-degree clockwise rotation about the origin followed by a translation 2 units to the right d. a 90-degree clockwise rotation about the origin followed by a translation 2 units to the left

Find the number of positive three-digit even integers whose digits are among 9, 8, 7,5, 3, and 1.

If cos(2x) = tan^2(y), show that cos(2y) = tan^2(x).