What is the value of z in the figure below?http://cdn.activelms.com/data/042c73b1-ddf5-4fd6-91e7-6c8434228f3d/Geometry%20Images/unit%2012-3%20q6.png

Question

ellamoyseyuk · Answer

i don't know how to start the problem

luffingsails · Answer

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Just so we can talk about it.

luffingsails · Answer

arc BC = 64 degrees
arc CD = 90 degrees
measurement at angle B = 85 degrees.
We don't know arc AD or AB (we want to know AB).

We can find AD first.

luffingsails · Answer

Since angle B = 85 degrees, what does arc AC measure?

ellamoyseyuk · Answer

170

luffingsails · Answer

Right... now subtract off arc CD and what we have left is arc AD.

ellamoyseyuk · Answer

180

luffingsails · Answer

Not quite... arc AC - arc CD = 170 - 90 = 80 degrees.

luffingsails · Answer

Now we now all of the circle except for arc AB (or z in your case). All we have to do is subtract all of the known angles from 360 degrees... what's left is z.

360 - 64 - 90 - 80 = z

ellamoyseyuk · Answer

126

luffingsails · Answer

Right. Make sense?

ellamoyseyuk · Answer

yeah thanks