when you know one measure of an angle, how can you find the measure of the other angles?

Question

Its a conditional statement
For example if M<7 = 135 degrees, then M<1 = ?.

OR

If M<11 =190 degrees, then M<8 = ? .

In my math book it says you can find the measure of all angles if you know the angle of just ONE angle. It doesn't explain how to do it though. Can someone please help?

sorry I meant 119 degrees ! for those of you that are confused !

Answer 1

Are you talking about triangles? It doesn't sound like it, because, in the second question, Angle 11 (?) is 190 degrees. Is there a diagram of some sort that we're missing here?

If the two angles are complementary, then they add up to 180 degrees. If they are supplementary, they add up to 360 degrees.

Answer 2

The book must be referring to the eight angles that are formed when two || lines are cut by a transversal.

If you start with the upper left angle and call it <1, then go clockwise and name the other 3 angles <2,<3,and <4 and then repeat this with the lower 4 angles calling them angles <5, <6, <7, and <8, then if yo know one ,, you can determine the rest.

Suppose yo know < 1 = 120 degrees. Then <3 = 120 degrees because vertical angles are equal. You also also know that <1 + <2 = 180 because theyare a linear pair. Thus <2 = 60 degrees and so does <4 because they are vertical angles

<4= <6 because alternate interior angles. Thus <6 = 60 degrees and so does <8 because they are vertical angles.
angle 6 and <5 are supplementary so <5 = 120 degrees as does its vertical angle, <7.

So knowing one angle allowed us to compute the other 7.

In general, the book is wrong to make such a statement unless it describes the particular case it is talking about

Answer 3

need at least an angle and a side, two angles, or two sides.

m<11 cant be 190 degrees unless an outside angle

Answer 4

well...isnt there 180 degrees in a whole triangle of angles????

Answer 5

You can use the pythagoreas theroem.