The idea being, when you run a perpendicular line to the base, from the right-angle in a right-triangle, like in this case, what you end up with is, three similar triangles, a Large triangle containing the two smaller ones, a Medium triangle and a Small one, check the picture below.
since all three are similar, we can use the proportions on the corresponding sides, as you see in the picture, the base of the triangle then will just be x + y.
the answer is:500
step by step explanation: i don't know if i'm right by the way
To find the percentage,here's what we can do:

The percentage would then be:
=63/420×100%
=3/20×100%
=0.15×100%
=15%
Therefore the answer is 15%.
Hope it helps!
Find the area of the fabric
The fabric is circular, so we find the area using the area of circle formula
a = π × r²
input the numbers
a = π × r²
a = 3.14 × (1.2)²
a = 3.14 × 1.44
a = 4.5216 ft²
Calculate the total cost
Multiply the cost by the area
cost = 5.4 × 4.5216
cost = 24.417
The total cost is approximately $24.42