Aquart of stain covers 100 square feet. how many quarts should you buy the stain the wheelchair ramp?

Saw the image of the wheel chair ramp. http://prntscr.com/aijltf

There are 2 shapes in the ramp. Right triangle and rectangle.

Triangle measurements : There are 2 triangles, left and right side of the ramp.
Long leg: 25 ft ; short leg: 25 inches

1 foot = 12 inches

25 inches * 1 ft/ 12 inches = 25 ft/12 = 2 1/12 ft

Area of the right triangle = ab / 2 = (25 ft * 25ft/12) ÷ 2 
A = (625 ft² / 12) ÷ 2 = 625 ft²/12 * 1/2 = 625 ft² / 24 = 26 1/24 ft²

Area of 2 triangles = 625 ft² / 24 * 2 = 1250 ft² / 24
⇒  52 2/24 or 52 1/12ft²

Area of Big Rectangle = Length * Width
A = 25 1/2 ft * 5 ft
A = 51/2 ft * 5 ft
A = 255 ft² ÷ 2 = 127 1/2 ft²

Area of small rectangle = Length * Width
A = 5 ft * 25 inches
A = 5 ft * (25 in * 1ft/12 in)
A = 5 ft * 25 ft/2
A = 125/2 ft² or 62 1/2 ft²

Sum of all Areas:
2 Triangles : 1250/24 ft² ⇒ 625/12 ft²
Big rectangle : 255/2 ft²
Small rectangle : 125/2 ft²

255/2 ft² * 6/6 = 1530/12 ft² ⇒ big rectangle
125/2 ft² * 6/6 =   750/12 ft² ⇒ small rectangle
625/12 ft² * 1/1 = 625/12 ft² ⇒ 2 triangles
Sum of 4 areas: 2,905/12 ft²

1 quart of stain covers 100 square ft.

2905/12 ÷ 100 = 2905/12 * 1/100 = 2905/1200 = 2.42 quarts needed to stain the wheelchair ramp.