I believe that b.Fractions are rational numbers is not true
sorry if its wrong
1,088 if you set it up as a proportion. It would be 17/20 compared to x/1280 multiply 17 by 1280 and then divide by 20.
This is the concept of transformations, given that ABC was rotated it implies that it retained it's original dimensions. This means that ABC is proportional to EFD. Therefore, given that EF=4.2 cm, DF=3.6 cm and DE=4.5 cm. The CB=FD=3.6 cm
Use Pythagorean Theorem:
c = sr (a^2 + b^2) = sr (3^2 + 5.3^2)
= sr (9 + 28.09) = sr (37.09)
= 6.09 = 6.1