Let G be some point on the diagonal line away from point E.
Angle DEG represents angle 1.
We're given that angle DEF is a right angle which means it's 90 degrees. Angle DEG is some angle smaller than 90 degrees. By definition, that must mean angle 1 is acute. Any acute angle is smaller than 90 degrees. There's not much else to say other than this is just a definition problem.
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Extra side notes:
If angle 1 was a right angle, then that would mean angle GEF would have to be 0 degrees; however the diagram shows this isn't the case.
If angle 1 was obtuse, then there's no way we'd be able to fit it into angle DEF. In other words, there's no way to have an angle larger than 90 fit in a 90 degree angle.
Answer:
Perimeter = 18 units
Step-by-step explanation:
one side = 4
other side² = 3² + 4² + 25
other side = √25 = 5
Perimeter = (2 x 4) + (2 x 5) = 18 units
Option 2.)
(Please correct me if I'm wrong)
2[5+2(8-6)]
2[5+2(2)]
2[5+4]
2[9]
18
