Question

On a piece of paper, use a protractor to construct right triangle DEF with DE=4 in., m∠D=90°, and m∠E=45°.

Answer 1

$\\ \tt\hookrightarrow tan45=\dfrac{DF}{DE}$

$\\ \tt\hookrightarrow 1=\dfrac{DF}{4}$

$\\ \tt\hookrightarrow DF=4in$

Option A is correct

Answer 2

Answer:

DF = 4 in

Step-by-step explanation:

As m∠E = 45° then DE = DF

Therefore, as DE = 4in, DF = 4 in

As DE = 4in  and  DF = 4 in,

then EF = $\sqrt{DE^2+DF^2} =\sqrt{4^2+4^2} =4\sqrt{2} \ \textsf{in}$