Comparing order of magnitude a biologist estimated the number of cells in a culture sample as 1.3 × 102. one week later, he looked at the same culture sample and estimated that the number of cells had grown to 3.9 × 105. determine how many times larger the culture sample was compared to a week earlier. (3.9 × 105) (1.3 × 102) complete the quotient in scientific notation and find the solution in standard notation. × =

Which term applies to agb and dge? a. obtuse b. supplementary c. complementary d. vertical

Corresponding angles are a. always b. sometimes c. never congruent

Given: ab ≅ cd and ad ≅ bc prove: abcd is a parallelogram. statements reasons 1. ab ≅ cd; ad ≅ bc 1. given 2. ac ≅ ac 2. reflexive property 3. △adc ≅ △cba 3. ? 4. ∠dac ≅ ∠bca; ∠acd ≅ ∠cab 4. cpctc 5. ∠dac and ∠bca are alt. int. ∠s; ∠acd and ∠cab are alt. int. ∠s 5. definition of alternate interior angles 6. ab ∥ cd; ad ∥ bc 6. converse of the alternate interior angles theorem 7. abcd is a parallelogram 7. definition of parallelogram what is the missing reason in step 3? triangle angle sum theorem sas congruency theorem sss congruency theorem cpctc