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Step-by-step explanation:

The length of EF is 1.98

Step-by-step explanation:

Looking at the right angle triangle DEF,

The hypotenuse is DF = 4.5

The adjacent side is DE

The opposite side is EF

The reference angle,# is 26 degrees.

To determine the length of EF, we would apply trigonometric ratio,

Sin# = opposite side/hypotenuse

Sin# is chosen because it contains the side that we want to determine and the given side. It becomes

Sin 26 = EF/4.5

Cross multiplying,

EF = 4.5Sin26 = 4.5 × 0.44 = 1.98

not only in mathematics, scientific proof also are required in the other field of science. also maths proofs are of particular structure, containing steps and logics. so proving is like doing science, it is science. that's why it is important to prove. 

an inaccurate proof leads to errors, or stating results that are not accurate.  which wil mess the probelm up you dont want this