Cylinder
Cone
Sphere
I guess
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.
3/9 because it is the same as 1/3 or 2/6.
Z+5 that's it sorry had to put at least 20 characters so good luck. To clarify, it is z+5
We are given one angle is 3 times less than other.
Let us assume one angle measure is x degrees and another is 4x.
Because x is 3x less than 4x. ( We can check 4x-x= 3x)
Sum of complementary angles is 90 degrees.
So, we can setup an equation
First angle measure + first angle = 90 degrees.
x+4x = 90.
Adding x and 4x, we get 5x.
So, 5x = 90.
Dividing both sides by 5, we get
5x/5 = 90.
x= 18.
So, one angle is of 18 degrees.
Another angle = 4x = 4 times 18 = 72 degrees.
So, required angles are of 18 degree and 72 degree.