Geometry Book-Chapter 4.3

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3.

2.

Exercises Set 4.3

1.

The circle representing Squares falls within the intersection of the circle representing Rhombi and the circle representing Kites .

Rhombi Squares Kite s

The circle representing Squares falls completely inside the circle representing Rectangles . The circle representing Rectangles falls completely inside the circle representing Parallelograms.

Paralle logra ms

Rectangle s

Square s

Three rhombi would be located within the circle All Sides Congruent . Three rectangles would be located within the circle All Angles Congruent . Three squares would be located within the intersection of the two circles.

All Side s

Congrue nt

All Angle s

Congrue nt

4.

5.

6.

7.

8.

9.e.

9.f.

9.g.

9.h.

9.a.

9.b.

9.c.

9.d.

9.i.

9.j.

9.k.

10.

By definition a rectangle is a quadrilateral with all congruent angles. The only possible way to construct a quadrilateral with four congruent angles is for those angles to measure 90° each. This means that the pairs of segments intersecting to form these angles are perpendicular to each other.

Furthermore, the segments opposite one another must be parallel to one another. Consequently, a rectangle is composed of two pairs of parallel lines. Hence, a rectangle is a parallelogram.

By definition a rhombus is a quadrilateral with all congruent sides. The only possible way to construct a quadrilateral with four congruent sides is for the segments opposite one another to be parallel to one another. Consequently, a rhombus is composed of two pairs of parallel lines.

Hence, a rhombus is a parallelogram.

Construct a horizontal line segment AB of length one unit. Construct a line perpendicular to segment AB and passing through point A. Construct a circle centered at point A and passing through point B. Label the point where this circle intersects the perpendicular line point D.

Repeat the constructions based at point A at point B. At this point you should have the unit square

ABCD. Next construct a circle centered at point A and passing through point C. Label the point where this circle intersects the line AB point E. Construct a line perpendicular to line AB and passing through point E. Label the point where this perpendicular line intersects line DC point F.

Rectangle AEFD is the initial Dynamic Rectangle . Construct the remaining Dynamic Rectangles in a similar manner using the diagonal of the current figure to establish the length of the succeeding figure.

Based on the SSS Theorem, each diagonal of a parallelogram divides the parallelogram into two congruent triangles. Consequently, the diagonals of a parallelogram intersect each other at their mutual midpoint. Hence, the diagonals of a parallelogram bisect each other.

Based on the SSS Theorem, each diagonal of a rectangle divides the rectangle into two congruent right triangles. All the right triangles constructed in this manner have congruent pairs of legs meeting to form the right angle. Based on the Pythagorean Theorem, the hypotenuse of each right triangle is congruent. Hence, the diagonals of a rectangle are congruent. sometimes true sometimes true sometimes true true sometimes true true true true never true true sometimes true

The two triangles are congruent because of the SAS Postulate.

12.

11.

These are just examples. Many other possibilities exist.

(a) (b) (c)

These are just examples. Many other possibilities exist.

(d)

(a) (b) (c)

(d) (e) (f)

13.a.

The Tangram Puzzle of Figure 4.3.5 can be used to construct the “house”. The right side of the roof is one of the large triangles. The left side of the roof is the parallelogram. The square sits on top of the parallelogram to make the chimney. The remaining four triangles form the base of the house.

13.b.

The Tangram Puzzle of Figure 4.3.5 can be used to construct the “duck”. The beak is one of the two small triangles and the head is the square. The neck is the parallelogram which rests upon the other small triangle. The breast is the mid-sized triangle and the two large triangles form the body.

13.c.

The Tangram Puzzle of Figure 4.3.5 can be used to construct the “whale”. The end of the tail is the mid-sized triangle. This rests on a small triangle which abuts the square. The top of the back is the other small triangle. The parallelogram forms the lower jaw. The two large triangles form the head and mid-section of the whale.

ITING AN OUTLINE

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