• Communications of Mathematical Education
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• v.21 no.3
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• pp.515-525
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• 2007

In this study, we study on equations of bisector and trisectors of angle. We analyze various studies related with bisector and trisectors of angle. As a result we have known that trisectors of angle is able to received by paper folding method. Using some concepts of vector we have described equations of bisector and trisectors of angle.

• The Mathematical Education
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• v.41 no.2
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• pp.215-225
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• 2002

In this paper we consider some properties of. bisector of interior angle(theorem 1) and exterior angle(theorem 2) in triangle by using analogy. As a result of analyzing various mathematics textbooks we have known that they focused not on relation between two theorems, but on describing two theorems. We have seen that theorem 2 is able to be inferred from theorem 1 by using analogy. After proving theorem 1 by some methods we analyze proof process, extract proof ideas, and analogize some ideas for proving theorem 2. From this we are able to find relationships between theorem 1 and 2.

• East Asian mathematical journal
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• v.26 no.2
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• pp.141-150
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• 2010

In this study, we study on the length of bisector of angle by the method using the area, the method using the vector and the method using the similarity, also the length of trisector of angle by the method using the sine law, the method using the area and the method using the second law of cosine in triangle, respectively. And we study on the length of trisector of angle with the length of bisector in angle. This study is expected to use the learning materials for the interesting construction and the problem solving using trigonometric functions.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.12
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• pp.1165-1172
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• 2009

The laminar boundary layer along a streamwise corner formed by two flat plates intersecting at right angle is measured by using Particle Image Velocimetry(PIV) technique. The free stream velocity ranges from 2.96m/s to 3.0m/s. The angle of incidence of the corner is set to 1.2 degree providing slightly favourable pressure gradient to ensure a laminar flow in the corner region. A round shape leading edge is used and the length of the model is about 1000mm. In the bisector plane, the measurement data show separation type velocity profiles having an inflection point which is a typical characteristic of laminar corner boundary layers. As the distance away from the bisector plane increases, velocity profiles are found to change into the Blasius profile. The change completes around half length of the boundary layer thickness in the bisector plane away from the bisector plane along the plate. In the bisector plane, the growth characteristic of the boundary layer thickness and the approximate similarity of velocity profiles are confirmed from the measurement data.

• Proceedings of the Korea Society of Mathematical Education Conference
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• 2010.04a
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• pp.151-163
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• 2010

This study is to provide improved teaching methods on classical geometric construction education by a straightedge and compass in school mathematics. In this paper, justifications of construction methods of Korean textbooks, for perpendicular bisector of an segment and angle bisector are discussed, which can be directly applicable to teaching geometric construction meaningfully. Based on these considerations, several implications for desirable teaching methods concerning geometric construction were suggested.

• East Asian mathematical journal
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• v.26 no.2
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• pp.151-164
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• 2010

This study is to provide improved teaching methods on classical geometric construction education by a straightedge and compass in school mathematics. In this paper, justifications of construction methods of Korean textbooks, for perpendicular bisector of an segment and angle bisector are discussed, which can be directly applicable to teaching geometric construction meaningfully. Based on these considerations, several implications for desirable teaching methods concerning geometric construction were suggested.

• The Mathematical Education
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• v.41 no.1
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• pp.79-90
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• 2002

In this article we study on connecting paper 131ding activities of triangle with mathematical proof Folding median, bisector of angle, and hight of paper triangle, we from and extract some ideas that help us to proof some important theorems of plane geometry. In this study using formed ideas in the process of paper folding activities, we suggest some interesting new mathematical proofs of the following theorems: 1. three medians of triangle are intersect in a point; 2. three bisectors of interior angles of triangle are intersect in a point; 3. three heights of triangle are intersect in a point.

• Communications of Mathematical Education
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• v.22 no.1
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• pp.27-39
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• 2008

In this paper we study triangle's properties related with angle bisectors, perpendiculars, circumcenter using the principle of the lever. We analyze proof method using the principle of the lever, and describe how to investigate intersection of segments, how to prove equalities and inequalities using the principle of the lever in triangle.

• Journal for History of Mathematics
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• v.17 no.3
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• pp.93-108
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• 2004

In this article we study on various proofs of the Steiner-Lehmus theorem(any triangle that has two equal angle bisectors is isosceles). We suggest 6 geometric proofs and 3 algebraic proofs of the theorem in detail, analyze these proofs, extract related theorems, proof ideas.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.34 no.5
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• pp.471-478
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• 2016

This paper proposes the results of analysis of correlation between satellite geometry elements for an effective use of satellite images. To achieve accurate positional information, stereo images have normal range of convergence and BIE (BIsector Elevation) angles which are greatly influenced by azimuth and elevation angle of individual image. In this paper, the variations of convergence and BIE angles are estimated according to azimuth angle differences between two images and each elevation angle. The analysis provided strong support for predicting stereo geometry without complex analysis of epiploar geometry or mathematics. The experiment results showed that more than 150°, 130°, and 100° azimuth angle differences need to be constructed when elevation angle of two images is 50°, 60°, and 70°, respectively, in order to make the convergence and BIE angle within normal range. The results are expected to be fully used for various application using stereo images.