Congruent angles

[rachelmaddie]

I need help with this question.
Would it be 22 = 3x + 11?

 

[firemath]

Well, you know that it all adds up to 90.
And obviously, 22 is less then 3x+11.
So you could say:
22+3x+11=90

 

[lev888]

We don't know that the two angles are equal. But we know that ...

 

[rachelmaddie]

So this is complementary angles?

 

[lev888]

So this is complementary angles?

Do you have any doubt that they are complementary angles?

 

[rachelmaddie]

Do you have any doubt that they are complementary angles?

No, but I don’t know how to give an explanation for that

 

[lev888]

No, but I don’t know how to give an explanation for that

You don't need to explain it - that's a given. See the red L shaped symbol? It denotes a 90 degree angle. So the sum of the 2 smaller angles is 90. Now you need to use this fact to set up an equation.

 

[rachelmaddie]

In the figure the two angles are complementary whose sums add up to 90 degrees.
Set up an equation to solve for x.
22 + 3x + 11 = 90
3x + 33 = 90
3x = 57
x = 19
Substitute the value of x to prove the equation is true.
22 + 3(19) + 11 = 90

Is this correct?