Posted by **James** on Thursday, October 8, 2009 at 3:00am.

Rewire each statement as two if-then statements that are converses of each other.

18. Two angles are supplementary if and only if the sum of their measures is 180.

20. (x-4)(x+6) = 0 if and only if x = 4 or x = -6

22. Theorem 2-5 may also be worded in this way: "If alternate interior angles formed by two lines and a transversal are congruent, then the lines are parallel." Write the converse of this statement. Is the converse true?

Tell whether you think each statement is true or false.

If false, draw a diagram that shows a counterexample.

If true, draw a diagram. List, in terms of he dram, what is given and what is to be proved. Do not write a proof.

24. If a triangle has two congruent sides, then the angles opposite those sides are congruent.

26. Two triangles have equal perimeters only if they have congruent sides.

28. If both pairs of opposite sides of a quadrilateral are paralell, then each side is congruent ot the side opposite it.

30. The diagonals of an equilateral quadrilateral are congruent.

In the conditional statement "if p, then q," p is said to be a sufficient condition for q to occur. Similarly, q is said to be a necessary condition for p. In Exercises 32-37 tell whether the first statement is necessary for the second statement, sufficient for it, or both necessary and sufficient for it.

Eg. First Statement and Second Statement

32. x > 4 and x is positive

34. Line l and m do not intersect.

36. A polygon is equilateral.

----------------------------------------------------

38. a) Given: Line AB ll Line DC; Line AD ll Line BC

b) Tell what is given and what is to be proved in the converse of part (a). Then write a proof of the converse.

c) Combine what you have proved in parts (a) and (b) into an if-and-only-if statement.

- Geometry - Conditional Statements/Proof -
**Reiny**, Thursday, October 8, 2009 at 8:13am
We do not do a student's assignments.

How about letting us know what answers you got, and I am sure somebody will tell you how you did.

I will do one of them for you.

**Two angles are supplementary** if and only if **the sum of their measures is 180.**

1. Two angles are supplementary if the sum of their measures is 180.

2. The sum of their measures is 180 if two angles are supplementary.

- Geometry - Conditional Statements/Proof -
**chris**, Sunday, October 16, 2011 at 8:39pm
false

## Answer this Question

## Related Questions

- Geometry - write two conditional statements that make up the following ...
- Geometry - Use the Law of Detachment to write a valid conclusion for the given ...
- Math - Find the measures of two supplementary angles if the difference of their ...
- Math - Part 1: Write two conditional statements for which the converse is true. ...
- physics (geometry bit) - h t t p : / / i m g 4 3 . i m a g e s h a c k . u s / i...
- Math Please Help - Which statement is not true? Two or angles that are ...
- Geometry - Two angles are supplementary if the sum of their measures is 180&#...
- Geometry - Use the Law of Detachment to write a valid conclusion for the given ...
- geometry - Rewrite the biconditional as a conditional statement and its converse...
- geometry - Lara wrote the statements shown in the chart. Statement One: If two ...

More Related Questions