Answer:
S.A = 147.35 cm²
Explanation:
Surface area of the triangular pyramid = base area + ½(perimeter of base*slant height)
Base area = ½*bh
b = 7 cm
h = 6.1 cm
Base area = ½*7*6.1 = 21.35 cm²
Perimeter of triangular base = 7 + 7 + 7 = 21 cm
slant height = 12 cm
Plug in the values into the equation
S.A = 21.35 + ½(21*12)
S.A = 21.35 + 126
S.A = 147.35 cm²