We have a pyramid with a base with an equilateral triangle.
To find the area of this triangle, we use the next formula:
![A_t=(Base\ast Height)/(2)](https://img.qammunity.org/2023/formulas/mathematics/college/m3rghf85mv6j6tueq938c225opjadgk8ge.png)
Looking at the given image, we can find that:
Base = 8cm
Height = 7 cm
Therefore, we can replace these values on the given equation:
![\begin{gathered} A_t=(\left(8cm\right?\ast\left(7cm\right?)/(2) \\ A_t=(56cm^2)/(2) \\ A_t=28cm^2 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/2p4e09emhvw6s4oxo81squyu1j082dk0qu.png)
The correct answer is the last option.