Pls help me 10 points

What are the measures of ∠a, ∠b, ∠c and ∠d? explain how to find each of the angle measure.

Scores on the cognitive scale of the bayley-scales of infant and toddler development range from 1 to 19, with a standard deviation of 3. calculate the margin of error in estimating the true mean cognitive scale score, with 99% confidence, if there are 12 infants and toddlers in a sample.

What is the area of a rectangle with vertices (-8,-2), (-3,-2), (-3,-6), and (-8,-6)? units