Congruent Parallelograms?

Although you may not be able to tell by the picture, these blue and yellow parallelograms are the tops of two led containers for my mechanical pencil. I traced them with help from the construct>parallel line, construct>perpendicular line, and construct>midpoint tools in The Geometer's Sketchpad.
I drew two altitudes (k and n) in order to find the height of each parallelogram. Then, I multiplied each height by its corresponding base and, to my surprise, found these parallelograms to not have equal areas, and therefore not be congruent.
The total area of parallelogram ACDF is 17.16 square centimeters.
(~GC2)

Baskets and Circles

I saw this basket that was holding oranges in my house and realized that it had an interesting design on it. The diameter is splitting the circle in half creating two congruent arcs. The other two chords in the circle share the same central angle. This means that the arcs would be congruent based off theorem 9-3, which is that if arcs share central angles then they are congruent. the chords would also be congruent because congruent arcs have congruent chords. (~KM5)

Arch

This is an example of two area's being added up to create one area. For example one of the problems  we had in the book that was about a free throw line. 

ABCD= 12

semicircle P1= 8

ABCD+P1= 20

(~CB5)

Drum Segment

In this picture of a drum head, I demonstrated how to find the segment.  First you find the area of the sector that you are dealing with, then you figure out what the area of the triangle is & subtract the area of the triangle from the sector area.  What is left should be the segment area. (~JG2)

Congruent Segments and Arcs

This is a semi-circle window that is in the front of my house. In this window the 3 segments CF, DF, and BF are congruent through the one central angle to the edge of the arc. Also in this picture the 4  angles coming out of the center point F are congruent to each other because of their congruent arcs and central angle. Note: the measurements are not exactly congruent because the point is not in the exact center of the window. (~AD1)

Almost Parallel...

Over spring break I got to go to Mexico and see some amazing sunsets. When I was looking back on the pictures of my vacation and found this, I noticed that the point where the sand and the water come together looked almost parallel to the horizon line. If two lines are cut by a transversal and the alternate interior angles are congruent, then the lines are parallel. When I measured out the angles, I found that they were very close but not completely congruent. So although it looks parallel just by looking at it, it's not quite. (~JC2)

Beijing Olympic Swimming Pool

This is the Beijing 2008 Olympic swimming pool. In the China trip we briefly saw it and I remembered that the outside of this building is a bunch of polygons put together on one giant rectangle. Unfortunately the pictures I took were bad so I found this good one.  (~DF)