You haven't provided the steps.
mathisfun.com/geometry/construct-linebisect.html
Here is a useful link to the correct steps. The instructions may not be exactly the same but I think you can do it.
Answer:
a. 4/21
b. 4/7
Step-by-step explanation:
Please kindly check the attached files for explanation.
The puppy weighs 48 ounces
Answer:
isosceles trapezoid
Step-by-step explanation:
1) find the distance of the points

AB = 
BC = |7-4| = 3
CD = 
AD = |9-2| = 7
2) equation of the line that passes threw BC
y = 7
3) equation of the line that passes threw AD
y = 5
conclusion
the quadrilateral has two parallel sides and two congruent sides, so it is a isosceles trapezoid