Given: Radius (r) = 3.4 cm, perimeter of sector 12.8 cm
To find: A(P-ABC)
Perimeter of sector = Iength of arc ABC + AP + CP
∴ 12.8 = l + 3.4 + 3.4
∴ 12.8 = l + 6.8
∴ l = 12.8 – 6.8 = 6cm
A(P - ABC) = (length of the arc x radius )/2
= (6 x 3.4)/2
= 10.2 cm2
∴ A(P-ABC) = 10.2 cm2