People were asked in a survey about their favorite car color. the results are shown in the bar graph.
altogether, how many people participated in the survey?
a.
20
b.
25
c.
50
d.
55

on your paper it doesn't say the answer but the the answer is altitude

step-by-step explanation:

area of part 1:

a1=base*height/2=(8+2)*(8-2-2-1)/2=10*3/2=15 ft^2

area of part 2:

a2=length*width=(8+2)*1=10 ft2

area of part 3:

a3=length*width=8*2=16 ft2

total shaded area : a1+a2+a3=41 ft2

total area of the reactangle : a=16*8=128 ft2

total area of the nonshaded region : 128-41=87 ft2