About 39 cats are in the shelter
A pyramid is regular if its base is a regular polygon, that is a polygon with equal sides and angle measures.
(and the lateral edges of the pyramid are also equal to each other)
Thus a regular rectangular pyramid is a regular pyramid with a square base, of side length say
x.
The lateral faces are equilateral triangles of side length
x.
The lateral surface area is 72 cm^2, thus the area of one face is 72/4=36/2=18 cm^2.
now we need to find
x. Consider the picture attached, showing one lateral face of the pyramid.
by the Pythagorean theorem:

thus,

thus:

(cm^2)
but

is exactly the base area, since the base is a square of sidelength =
x cm.
So, the total surface area = base area + lateral area =

cm^2
Answer:

cm^2
The sum of the inner angles of any triangle is always 180°, i.e. you have

In the particular case of an equilater triangle, all three angles are the same, so

and the expression becomes

which implies 
So, if you rotate the triangle with respect to its center by 60 degrees, the triangle will map into itself. In particular, if you want point A to be mapped into point B, you have to perform a counter clockwise rotation of 60 degrees with respect to the center of the triangle.
Of course, this is equivalent to a clockwise rotation of 120 degrees.
Finally, both solutions admit periodicity: a rotation of 60+k360 degrees has the same effect of a rotation of 60 degrees, and the same goes for the 120 one (actually, this is obvisly true for any rotation!)
1.) 3/4
2.) It snowed 1/4 more on Tuesday than it did on Monday.