Answer:
1350 square inches
Explanation:
The area of the end trapezoid is ...
A = (1/2)(b1 +b2)h = (1/2)(12 +36)(5) = 120 . . . . . square inches
The perimeter of the end trapezoid is ...
P = 13 +12 +13 + 3×12 = 74 . . . . inches
so the total area of the rectangular surfaces (including the bottom) is ...
(74 in)(15 in) = 1110 in²
The total area of the ramp is this rectangular area plus the two trapezoidal ends:
total area = rectangle area + 2×trapezoid area
= 1110 in² +2×120 in²
total area = 1350 square inches