Geometry

posted by .

Writing indirect proofs.
Can someone please check for me. I am not sure If this is correct.Thanks much

Given: triangle ABC angle B=120 degree
Proof: Triangle A does not equal 60 degree
Plan: Using an indirect proof, using the paragraph method

My answer.
Assume temporarily that Measure angle A = 60. Then measure angle C=60,
and measure angles A+B+C=180= 60+B+60=180. Therefore the temporary assumption that measure angle A=60 is false. It fallows that measure angle 60 does not equal 60 degrees

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Geometry

    Given: in triangle ABC, angle B= 120 degrees Prove: angle A does not= 60 degrees Plan: use indirect proof Assume temporarily that Measure angle A = 60. Then measure angle C=60, and measure angles A+B+C=180= 60+B+60=180. Therefore the …
  2. math- Triangle facts

    Explaining the isosceles theorem. Explain why the SAS Inequality theorem is also called the Hinge theorem. the steps for Indirect Proofs and using an indirect proof with an algebraic problem.
  3. geometry

    TWO COLUMN TRIANGLE PROOF Given: line AB is parallel to line DE, and line AD bisects line BE Prove: triangle ABC is congruent to triangle DEC by using the ASA (angle-side-angle) postulate
  4. Geometry

    The shape is a triangle with a line in the middle. How do I write an indirect proof with this information?
  5. Geometry

    Indirect Proofs Prove a triangle cannot have 2 right angles. 1) Given triangle ABC. 2) Assume angle A and angle B are both right angles is true by one of two possibilities (it is either true or false, so we assume it is true) This …
  6. Geometry

    Write an indirect proof that an obtuse triangle does not have a right angle. Given: Triangle RST is an obtuse triangle. Prove: Triangle RST does not have a right angle. Let angle S be an obtuse angle. Assume Triangle RST has a right …
  7. geometry

    Indirect proof given triangle ABC,<B is an obtuse angle prove there can only be one obtuse angle in triangle.
  8. geomatry

    in triangle abc angle c is 90.write a indirect proof that angle a is less than 90.
  9. geometry

    Given: In triangle ABC, <A=135 degree Prove: <B is not equal to 45 degree ( Write an indirect proof)
  10. geometry

    The medial triangle of a triangle ABC is the triangle whose vertices are located at the midpoints of the sides AB, AC, and BC of triangle ABC. From an arbitrary point O that is not a vertex of triangle ABC, you may take it as a given …

More Similar Questions