Wie alt Sie, Herr Maier? Ich 45 Jahre alt. sind/bin
seid/sind
bist/ist
sind/sind

Sind/bin

Wie alt sind Sie, Herr Maier? Ich bin 45 Jahre alt.

Please refer to my answer from your last question for the explanations for Sind, bist, seid and ist:

Bin is used if the subject is ich (I)

Example:

Ich bin 45 Jahre alt = I am 45 years old

answer:

a=1/2h(b1+b2) or a=1/2(b1+b2)h

explanation: to find the area of a trapezoid, multiply the sum of the bases (the parallel sides) by the height (the perpendicular distance between the bases), and then divide by 2.

(i hope this ! : )