#6
Vertical angles are the angles opposite each other when two lines cross.
Let's see which angle forms a "X" with ∠EOD:
So, ∠COF is "vertical" with ∠EOD.
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#7
When 2 angles add up to 90 degrees, we say that they are complementary angles.
Since ∠POF + ∠FOB = 90, then ∠POF is complementary to ∠FOB.
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#8
∠BOC + ∠AOC is a straight angle (straight line).
A straight angle is 180 degrees.
So, we can write,
We know ∠BOC = 150, so ∠AOC will be,
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#9
From the diagram, we can see that ∠EOA and ∠FOB are vertical angles. Thus, they are equal.
Since ∠EOA = 37,
∠FOB = 37
Now, from the diagram, we can see,
∠FOA + ∠FOB = 180 [since they are straight line]
Now, we can easily find ∠FOA:
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#10
Adjacent angles are two angles that have a common side and a common vertex (corner point) but do not overlap in any way.
For example,
∠1 and ∠2 are adjacent angles.
From our diagram,
∠HGO is adjacent to ∠EGH
From the diagram above, we see that G is the common vertex and GH is the common side.
Thus,
∠HGO is adjacent to ∠EGH
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#11
From the diagram, we see that ∠EGH and ∠HGO fall in a straight line. So, they add up to 180 degrees.
Given,
∠HGO = 128,
Let's find ∠EGH:
Given,
We can say:
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#12
From the figure, we see that ∠EOA + ∠EOD + ∠DOB = 180 degrees [straight line].
Given,
∠EOA = 67
∠DOB = 29
We can solve for ∠EOD:
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#13
When 2 angles add up to 180 degrees, we say that they are supplementary angles.
Given,
∠AOD + ∠DOB = 180
We can say that ∠AOD is supplementary to ∠DOB.
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#14
Since ∠COF is congruent to ∠DOF and fall is a straight line, we can say that they are each 90 degrees.
Thus, FO and CD will be perpendicular to each other.
So, we can say,
FO is perpendicular to CD
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#15
Given,
∠COP = 72 and ∠POF = 31, we have:
We want to know the measure of ∠EOD.
Let's see below:
We see that ∠COF and ∠EOD are vertical angles.
Vertical angles are equal.
So,
∠EOD = ∠COP + ∠POF
∠EOD = 72 + 31
∠EOD = 103°
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