Part A:
The new deck will be a 4:5 scaled version of the original deck. This means that every dimension of the new deck will be 4/5 times the corresponding dimension of the original deck.
The original deck has a base of 15 feet and a height of 9 feet.
The new deck will have a base of (4/5) * 15 = 12 feet and a height of (4/5) * 9 = 7.2 feet.
Therefore, the dimensions of the new deck are 12 feet for the base and 7.2 feet for the height.
Part B:
To find the area of the original deck, we use the formula for the area of a triangle:
Area = (1/2) * base * height = (1/2) * 15 * 9 = 67.5 square feet.
To find the area of the new deck, we use the same formula with the new dimensions:
Area = (1/2) * 12 * 7.2 = 43.2 square feet.
Therefore, the area of the original deck is 67.5 square feet, and the area of the new deck is 43.2 square feet.
Part C:
The ratio of the areas is:
Area of new deck / Area of original deck = 43.2 / 67.5
Simplifying this fraction, we get:
Area of new deck / Area of original deck = 8 / 15
The scale factor is 4/5, which simplifies to 8/10 or 4/5.
Comparing the ratio of the areas to the scale factor, we see that:
Area ratio / Scale factor = (8/15) / (4/5) = (8/15) * (5/4) = 1
Therefore, the ratio of the areas is equal to the scale factor. This makes sense since the area of a triangle is proportional to the square of its dimensions. In this case, the scale factor is applied to both the base and the height, so the area ratio is equal to the scale factor squared, which is 16/25.