First you have to find the total amount of books in the sample which is 1125 then you can see that 45 of those books have major damage. Next you need to divide 58,500 by 1125 to see how much you need to multiply 45 by which is 52. So now you need to multiply 45 by 52 which is 2340.
The area of a triangle can be calculated by multiplying the triangle's base by its height, and then dividing the result by . As an algebraic expression, this would be , where is the triangle's base and is the triangle's height. In this case, we know that and . Therefore, the area of this triangle is square units. Hope this helps!