So we have:
To find the area of the entire figure we can simply find the areas of each individual subfigure.
For rectangle A we have that its area is given by:
![S_A=5in\cdot10in=50in^2](https://img.qammunity.org/2023/formulas/mathematics/college/h1dalf6bi60nlazm0m7vl9j960k4pmpixp.png)
For rectangle B:
![S_B=7in\cdot x](https://img.qammunity.org/2023/formulas/mathematics/college/2ctsww86k990l70ri6bzvuit8lb4tzhx3v.png)
Where side x is given by:
![\begin{gathered} x+6in=10in \\ x=10in-6in=4in \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/yrabfv39nojpg78zwb1wau3dvb3icfcfw9.png)
Then the surface of rectangle B is:
![S_B=7in\cdot4in=28in^2](https://img.qammunity.org/2023/formulas/mathematics/college/xdtcj71encuroeumx8m05czgfwsla29gqb.png)
C is a triangle, the area of a triangle is given by its base (y) times its height (x) divided by two:
![S_C=(x\cdot y)/(2)=(4in\cdot y)/(2)](https://img.qammunity.org/2023/formulas/mathematics/college/lwpsyci3jyv1inwse8derjorbkvbk9rlsz.png)
We need to find y using the length of the base of the total figure:
![\begin{gathered} 15in=7in+5in+y=12in+y \\ y=15in-12in=3in \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/cpg0jls20y6md551vjlmaig5kjdpf3va9r.png)
Now that we found y we can find the area of the triangle:
![S_C=(4in\cdot y)/(2)=(4in\cdot3in)/(2)=6in^2](https://img.qammunity.org/2023/formulas/mathematics/college/uwuk2vs2z87yw8nwbokhytchzlex3p8uy1.png)
The total area is then:
![S_A+S_B+S_C=50in^2+28in^2+6in^2=84in^2](https://img.qammunity.org/2023/formulas/mathematics/college/dft5zl1jcdiism5njppvqioymm9a2xw9sf.png)
So the total area is 84 square inches.