the diagonals of quadrilateral abcd intersect at point k. is each statement needed to prove that abcd is a parallelogram?

In a class, there are 12 girls. if the ratio of boys to girls is 5: 4 how many boys are there in the class

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?

What is the area of a triangle with a base of 7x and height of 8x expressed as a monomial? question 5 options: 1x 15x2 28x2 56x2