Which of the following sets of angles of a triangle represents an acute triangle?
a. 30°, 60°, 90°
b. 45°, 40°, 95°
c. 40°, 40°, 100°
d. 60°, 65°, 55°

Find the area of the regular hexagon if a side is 20 cm.

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.

Select all of the following expressions that are equal to 2.5.