8x^2 - 16x - 15 = 0
x = [ -(-16) +/- sqrt((-16)^2 - 4*8*-15) / ] 2*8
= 2.696, -0.696
The area of a parallelogram is the product of the length of the base and the height measured perpendicular to the base.
1i) (20 cm)*(12 cm) = 240 cm^2
2ii) (7 cm)*(7.5 cm) = 52.5 cm^2
3iii) 27 cm^2 = (6 cm)*h
.. h = (27 cm^2)/(6 cm) = 4.5 cm