Three polygons have been divided into triangles by drawing a
segment from one vertex to all nonadjacent vertices. If n is the
number of sides in the polygon, which expression shows the
number of triangles created by each polygon?
A. n
B.(n + 2)
C.(n - 2)
D.3n, 4n, 8n

Answer question above and explain each step : )

Bring the fraction a/a-4 to a denominator of 16-a^2

Amira is painting a rectangular banner 2 1/4 yards wide. the banner will have a blue background. amira has enough paint to cover 1 1/2 square yards of the wall. the school colors are blue and yellow, so amira wants to add yellow rectangles on the left and right sides of the blue rectangle. the yellow rectangles will each be 3/4 yards wide and the same height as the blue rectangle. what will be the total area of the two yellow rectangles?