A = bh means area = base x height, which is the formula for the area of a parallelogram (or rectangle or square, which are special types of parallelogram).

The problem gives you two of these values:  A = 45 and b = 15

Plug these values into the area formula to calculate the height:

A = bh

45 = 15h          substitue the values given for area and base

3 = h               divide both sides of the equation by 15 to get h by itself

So, height is equal to 3.

One thing to remember about a parallelogram (although you don't need to know it for this particular problem), is that the height is not the same as the lenth of the sides which are not the base, unless the parallelogram is also a rectangle or square.  The height is the length of a line segment that is perpendicular to the base and connects the base with the side parallel to it.  I wish I could show you this in a diagram, but that is not possible here.

In any parallelogram or rectangle, the area (A) is the product of its base (b) and height (h). You just need to exactly substitute any given from the information.

So, if A = 45, b= 15, and A = bh, then

                                    45 = (15)h, solve for h

                                 divide both sides of the equation by 15, hence

                                 45/15 =15h/15

                                      3 = h

The A=bh looks like Area = Base X Height which is the formula for the area of a rectangle (or parallelogram). Assuming that then the Area is given as 45 and the Base is given as 15, the Height could then be found as 45/15=3.

If you are given the area of a parallelogram as 45, and the base as 15, then you need to find the length of the height. The formula is A=bh, so substituting 45 for A and 15 for b, you get 45=15h. Now, you will solve for h by dividing both sides by 15. Thus, 3=h.