How much is the length of AC

[eddy2017]

Hi, Can anyone help me reason this question?
In a triangle ABC, the side BC is 3 cm long, the angle at A measures 70° and the angle at C measures 40°. How much is the length of AC ?

I think that seeing as all the angles in a triangle when added should give 180 the angle b is 70 degrees.
The length of AC IS 3 cm long too.

Is this correct?

Thanks,
eddy

 

[Dr.Peterson]

Hi, Can anyone help me reason this question?
In a triangle ABC, the side BC is 3 cm long, the angle at A measures 70° and the angle at C measures 40°. How much is the length of AC ?

I think that seeing as all the angles in a triangle when added should give 180 the angle b is 70 degrees.
The length of AC IS 3 cm long too.

Is this correct?

Yes. You've shown that it is an isosceles triangle.

 

[eddy2017]

Thanks a lot, Dr Peterson.

 

[R.M.]

Correct. Draw a picture. Observe the two congruent angles; the sides opposite those angles must be congruent.

 

[eddy2017]

Right. Thanks a lot, R.M.