The degree of a polynomial is the highest number as an exponent in a term, for example, 5x^3+5x^2, 3 is the degree. To find it, you need to either just find the highest number or add up multiple degrees in one term. An example of this is 5x^3y^3+4x^3y^2. Since 3+3=6 and 3+2=5, the first term has the highest degree.
let's say the two numbers are x and x + 9. so we know x + x + 9 = 21, so 2x + 9 = 21. subtract 9 from both dies to get 12 = 2x. divide both sides by 2 to get x = 6. so your two numbers are 6 and 15.
The answer is a 36
This is because if you take the area of one of the three triangles that make up the trapezoid you do 1/2 base times height and get 12 and you add all three together thus getting 36 square inches
Area of a rectangle can be calculated by multiplying the length by the height.
So:
l x w
3 x 13
39 cm squared
Area of a triangle can be calculated by multiply the length by the height and dividing by two. So:
1/2 x l x w
1/2 x 10 x 8
40 m squared