Need math help asap, an explanation would also be much appreciated, thanks.

Use the angle bisector theorem. In this case, it says

3 / (8 - y) = 9 / y

Solve for y :

3y = 9 (8 - y)

3y = 72 - 9y

12y = 72

y = 6

Area of the house and porch is 875 square feet.

Step-by-step explanation:

Given question is incomplete: find the complete question in the attachment.

From the figure attached,

Area of the octagonal house and porch = Area of the rectangle - Area of two rectangles cut off from the top corners of the rectangle

Area of the rectangle = 30×30 = 900 square feet

Area of the triangles =

                                  = 25 square feet

Area of the house and porch = 900 - 25

                                                = 875 square feet

Therefore, area of the house and porch is 875 square feet.