Respuesta :
box number one: given
box number two: angle addition postulate
box number three: 51 degrees + 39 degrees = m DEF
box number four: 90 degrees = m DEF
box number five: DEF is a right angle
box number six: definition of a right triangle
just took the test and these are the correct answers, hope i helped :)
Solution:
Given : ∠ D E G= 51°, ∠GEF=39°
To prove: Δ D E F is a right triangle.
Proof:
A right angle triangle D E F.
∠ D E F =90°.
Point G is on segment D F, and segment E G is drawn.
Now, taking ∠DEG and ∠GEF into consideration,
∠DEG=51° and ∠GEF=39°→→(Given)
∠DEG + ∠GEF =
∠DEF=51° + 39°
∠DEF=90°,showing Triangle D E F is a right triangle.