A metalworker is creating decorative points in the form of triangular pyramids to go on top of a fence she is building. She wants to know the surface area of each pyramid. Use the surface area formula to find the surface area of each pyramid based on the figure.
b=4.5
l=3.5
a=3.9
Using the formula: SA=1/2 ab+3(1/2 lb)
So, it would be SA= 1/2 3.9*4.5+3(1/2 (3.5*4.5) )
It gives me: 32.4 cm^2