Answer:
298.5 cm^2.
Step-by-step explanation:
The area of the triangular base
= 1/2 * base * height
= 1/2 * 10 * 8.7 cm^2
There are 3 other triangular sides all withe the same area and each of them as area = 1/2 * 10 * 17
So the total surface area of the pyramid
= 1/2 * 10 * 8.7 + 3 * 1/2 * 10 * 17
= 5 * 8.7 + 3 * 85
= 298.5 cm^2.
