Height of the trapezoids = sqrt (17^2 - 8^2) = 15cms
base = 19 cms
(b) area of each trapezoid = 15/2 (35 + 19) = 405 cm^2
Total area painted blue = 2*405 = 810 cm^2
(c) length of the edges of one trapezoid = 35 + 19 + 2(17) = 88 cms
So one piece of sandpaper ( can sand up to 80 cm) will not be enough to sand all of the edges.
Answer:

Step-by-step explanation:
Product of of 3 and b is 3b
At least means greater than or equal too.

I hope this helps you
Euclid
h^2=4.6
h=2 square root of 6
h^2+6^2=base^2
24+36=base^2
base=2square root of 15
h^2+4^2=height^2
24+16=height^2
height=2 square root of 10