This is worth 25 plz answer. what is a ratio?

Fractions can be added and subtracted only if they're fractions. a. like b. proper c. improper d. unlike

How do the definitions, properties, and postulates you've learned about line segments, parallel lines, and angles to define the shapes of polygons

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?