Please help me with my homework

A) 30 cm^2.

B) 100 cm^2.

C) 450 cm^2.

Step-by-step explanation:

A)  As all the sides of an equilateral triangle are equal the lateral area consists of 3 rectangles of size 4*2.5 cms.

Lateral area of the prism = 3 * 4 * 2.5 = 30 cm^2.

B)  There are 4 rectangles making up the lateral area because the base is square. The height = 125 mm = 12.5 cm.

Lateral area = 4 * 2 * 12.5 = 100cm^2.

C) Since a regular pentagon has 5 equal sides the lateral area consists of 5 rectangles. each of  area  6*15 = 90 cm^2.

Lateral area = 5 * 90 = 450 cm^2.