An octahedron and its net are shown below. All the faces are the same size and shape. What is the surface area of octahedron? Please answer !!

Explanation:

There are 8 identical triangles shown here (ignore the dashed vertical line). We know they are identical because of the phrasing "same size and same shape". In other words, the triangles are congruent.

Each triangle has base 12 cm and height 10.4 cm

So the area of each triangle is base*height/2 = 12*10.4/2 = 62.4 square cm.

In total, all 8 triangles combine to an area of 8*62.4 = 499.2 square cm which points us to choice D

3< x< 5

step-by-step explanation:

|x - 4| < 1

there are two solutions, one positive and one negative.   remember to flip the inequality when taking the negative solution

x-4 < 1       x-4 > -1

add 4 to each side

x-4+4 < 1+4       x-4+4 > -1+4

x< 5                 x> 3

3< x< 5