Answer:
![82,8m^2 = S.A](https://img.qammunity.org/2020/formulas/mathematics/middle-school/ui6xvajygfpc6z3ddj3un1nww2kp73inyu.png)
Explanation:
Area of a Rectangle:
![hb\:or\:wb = A](https://img.qammunity.org/2020/formulas/mathematics/middle-school/etbftr4kwoi56629fdksslsvvyua8vashc.png)
Area of a Triangle:
![(1)/(2)hb; (1)/(2)bh, or\: (hb)/(2) = A](https://img.qammunity.org/2020/formulas/mathematics/middle-school/1aonprob7lra5zwss7251wkk20r41t1esy.png)
Need to know
- Two small triangles
- Two big triangles
12m² = Rectangle
26,4m² EACH = Big Triangles
9m² EACH = Small Triangles
![2[9] + 2[26,4] + 12 = 18 + 52,8 + 12 = 82,8](https://img.qammunity.org/2020/formulas/mathematics/middle-school/pom0n53wyy17ze9lsas4wngmr25uu74nku.png)
So, the surface area of the rectangular pyramid is 82,8m².
* The answer is not 85,31 because this rectangular pyramid has two slant heights. If we ONLY had 9 as ONE SLANT HEIGHT, then the answer would have been 85,31, otherwise it is incorrect.
I am joyous to assist you anytime.