Answer:
145.0 cm^2
Step-by-step explanation:
Given data
r= 4cm
l= 5cm
h=??
Apply Pythagoras theorem to find h we have
h^2= 4^2+5^2
h^2= 16+25
h^2= 41
h=√41
h= 6.4cm
Substitute into the formula for the surface area of cone
A=πr(r+√h^2+r^2)
A=3.14*4(4+√6.4^2+4^2)
A=12.56(4+√40.96+16)
A=12.56(4+√56.96)
A=12.56(4+7.547)
A=12.56*11.547
A=145.0 cm^2
