Proofs without words:exercises in Visual thinking (V.1 and V.2)

Here are hand-drawn and some of the pictures, from the title of the two books, in the library cursory browsing for half an hour, the one can see the pick here, and then more complex feelings against the original intention of no word proof, there is no excerpt:

Pythagorean theorem

Hippocrates ' theorem:

An infinite step, a corner of three equal portions:

The pentagram is 180 degrees in angle:

Total Square:

Cosine theorem:

Half-width formula:

The and of the inverse tangent function:

Mean value theorem:

A positive number and its reciprocal sum of at least 2:

Integer sum:

Square Square: The area of the small square = the area of the 1/5 Square, which connects the vertices of the square to the midpoint of the edge.

Two ways to right triangle the radius of the inner circle:

Here ab/(a+b+c) = (a+b-c)/2, can derive the Pythagorean theorem (another way of proving)a^2+b^2 = c^2.

Exponentially

The sum of squares of the Fibonacci sequence:

Do you realize the wonderful beauty of mathematics:-?

Proofs without words:exercises in Visual thinking (V.1 and V.2)