Consider the surface area of the pyramid shown.
a) draw a net for the pyramid. label all sides with measurements.
b) write an expression for the surface area of the pyramid and then find the surface area.

To draw the net, you will "open up" the figure to create a net that looks like the attached picture.  It does not say that this is a square pyramid, but the net is drawn with that in mind.

To find the area of all the surfaces, you will find the areas of the 4 congruent triangles (the lateral faces) and the area of the square base.

Area of square base:  
A = lw
       3 x 3 
A = 9 square cm

Area of 1 lateral face (triangle)
A = 1/2 x b x h
       1/2 x 3 x 2.24
A = 3.36 square cm

3.36 x 4 = 13.34 square cm

13.34 + 9 = 22.44 square cm

Element 17 is chlorine it is a group 7 element(halogen) and belongs to period 3 of the periodic table