Answer:
The surface area is 55 cm².
Step-by-step explanation:
The formula to compute the surface area of the triangular pyramid is:
[tex]SA=(0.50\times \text{Base Perimeter}\times h)+\text{Base Area}[/tex]
Here h is the slant height.
Compute the Base perimeter as follows:
Perimeter of the equilateral triangle = 3 × side
= 3 × 4
= 12 cm
Compute the Base area as follows:
Area of the equilateral triangle = 0.50 × side × height
= 0.50 × 4 × 3.50
= 7 cm²
Compute the surface area as follows:
[tex]SA=(0.50\times \text{Base Perimeter}\times h)+\text{Base Area}[/tex]
[tex]=(0.50\times 12\times 8)+7\\=48+7\\=55\ \text{cm}^{2}[/tex]
Thus, the surface area is 55 cm².