Download
copying an angle n.
Skip this Video
Loading SlideShow in 5 Seconds..
Copying an Angle PowerPoint Presentation
Download Presentation
Copying an Angle

Copying an Angle

97 Views Download Presentation
Download Presentation

Copying an Angle

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. Copying an Angle ZacCoblentz 5th hour Mr. Novak Honors geometry

  2. Step 1 Start with angle BAC that we will copy.

  3. Step 2 Make a point P that will be the vertex of the new angle.

  4. Step 3 • From P, draw a ray PQ. This will become one side of the new angle. • This ray can go off in any direction. • It does not have to be parallel to anything else. • It does not have to be the same length as AC or AB.

  5. Step 4 Place the compass on point A, set to any convenient width.

  6. Step 5 Draw an arc across both sides of the angle, creating the points J and K as shown.

  7. Step 6 Without changing the compass width, place the compass point on P and draw a similar arc there, creating point M as shown.

  8. Step 7 Set the compass on K and adjust its width to point J.

  9. Step 8 Without changing the compass width, move the compass to M and draw an arc across the first one, creating point L where they cross.

  10. Step 9 Draw a ray PR from P through L and onwards a little further. The exact length is not important.

  11. Done. The angle ∠RPQ is congruent (equal in measure) to angle ∠BAC.

  12. Proof Line segments AK, PM are congruent Line segments AJ, PL are congruent Line segments JK, LM are congruent Triangles ∆AJK and ∆PLM are congruent Angles BAC, RPQ are congruent. Both drawn with the same compass width. Three sides congruent (triangle SSS postulate) CPCTC postulate. Corresponding parts of congruent triangles are congruent