PLEASE HELP ME WITH AN EXPLANATION

Step-by-step explanation: View this in 3 dimensions, top, front, and right. Adding these 2d surface areas and multiplying by 2 will give the surface area of the entire figure. From the top, there are 6 squares, each square has 5in side length so the area of the total is 5^2 x 6 = 150. From the right, there are 3 squares for 5^2 x 3 = 75. From the front are 4 squares, so 5^2 x 4 =100. 2(100+150+75)= 650in

b. b < 1 might be the correct answer

11) obtuse

13)right

15) acute