What’s the volume of the composite figure of the triangle? 4x8x12

Ade and abc are similar. which best explains why the slope of the line between points a and d is the same as the slope between points a and b?

I’m really confused and need to learn this

Summary statistics given for independent simple random samples from two populations. use the pooled t-interval procedure to obtain specified confidence interval. x1=71.6, s1=3.9, n1=11, x2=67.9, s2=3.4, n2=9 determine a 99% confidence level.