Which biconditional is not a good definition?

a.) an angle is a right angle if and only if its measure is 90 degrees.
b.) an angle is acute if and only if is between 0 and 90 degrees.
c.) two angles are congruent if and only if their measures are the same.
d.) an angle is obtuse if and only if its measure is greater than 180 degrees.

Simplify. 4+3/7x-2-2/7x a. 2-5/7x b. 6-1/7x c. 2+1/7x d. 6+5/7x

Which number line correctly shows 0.8 + 0.3?

Will mark determine whether the conjecture is true or false. give a counterexample for any false conjecture. given: points r, s, and t conjecture: r, s, and t are coplanar. a) false; the points do not have to be in a straight line. b) true c) false; the points to not have to form right angles. d) false; one point may not be between the other two.