Someone is this right.
i answered:

a) how much material does he need to cover one rectangular side of the tent?
justify your answer using equations/formulas, models, and/or words to explain your mathematical reasoning.
lets say the area = x. so the area of the rectangular side is x = 9 times 6. so x = 54. : ) area (or x) always equals length times width, so it would be 9 times 6.

b) if david’s dad wanted to re-cover the whole tent, how much material would he need? justify your answer using equations/formulas, models, and/or words to explain your mathematical reasoning.
you have to find the areas of each face of the tent individually and then add them together. so first, lets take the triangular sides of the tent. we can find the area of them combined if we multiply by 2.

so your formula would 2(1/2 times 7 times 6). that is equal to 42.
then for the rectangular sides, 2( 9 times 6). that is equal to 108.
so add those together. 42 + 108 = 150. so they would need 150 square feet of tent to recover the whole tent.

c) if david found a roll of tent material in the garage that was 65 ft2, would he have enough material to cover the entire tent? explain your reasoning.
the answer is no. 150 > 65. there would be 95 feet of tent more needed to cover the tent.

This is fairly easy. You simply need to solve the area of each side of the tent. 
Based on the illustration, the tent has 5 sides. 2 sides are triangles and 3 sides are rectangles.

We need to get the dimension of each side. 

Both triangles have the same dimensions. Its height is 6 feet. Its base is 7 feet. Its side is 6 feet.

Of the 3 rectangles, 2 have the same dimensions. The different rectangle is the floor of the tent.

2 rectangles have these dimensions: Its length is 9 feet and its width is 6 feet.

The other rectangle has a length of 9 feet and width of 7 feet.

Answer to question A: 
Find the area of the rectangle where the damage is located:
Area of a rectangle = Length * width
Area of a rectangle = 9 feet * 6 feet = 54 square feet.

Answer to question B:
We need to find the area of each side:
Area of the floor rectangle = length * width = 9 feet * 7 feet = 63 square feet.
Area of the triangle = (height * base) / 2 = (6 feet * 7 feet) / 2 = 21 square feet.
Since there are two triangles, we multiply the area of the triangle by 2. 
21 square feet * 2 triangles = 42 square feet.
We already solved the area of the rectangle in Question A. So, we simply need to multiply it by 2 to get the area of both sides.
54 square feet * 2 rectangles = 108 square feet

We get the total area of each side by adding them up.
63 sqf + 42sqf + 108 sqf = 213 square feet 

Answer to question C: 
No, the 65 square feet material is not enough to cover the whole tent.

As solved in Question B, they need a total of 213 square feet of material. Taking in consideration the 65 square feet material they found, they still need to buy an additional 148 square feet of material.

213 sqf - 65 sqf = 148 sqf