## dellzasaur 3 years ago What is the value of G? (GEOMETRY HELP!) 34 46 56 88

1. dellzasaur

2. dpflan

What do the tick marks on the triangles signify?

3. campbell_st

the triangle with is 88 degree angle is isosceles so the base angles are equal and each is 46 degrees angle G is vertically opposite a base angle of 46 so G = 46 degrees

4. dellzasaur

If they're congruent or the same I think & thank you very much @campbell_st !!! Really helpful :)

5. campbell_st

@dellzasaur the triangles aren't congruent as the left have triangle will has base angles in the isosceles triangle of 67 degrees

6. dpflan

In this case, the signify that the sides are the same length. That makes each triangle an isosceles triangle, and as @campbell_st pointed out so well, that means there is a nice relationship among the angles in each triangle.

7. dpflan

You are given 88 degrees, and you know that a triangle has 180 degrees in total for the interior angles. So, you needed to determine the degrees of the other angles. So 180-88 = 92 degrees, the remaining amount of degrees for the two other angles to sum to. But, the triangle is, again, isosceles, so we know the two other angles have the same degree. So, 92 / 2

8. dpflan

So, @campbell_st gave you the answer in one go, but do you understand how the answer was obtained? Do you feel that you can do another similar question?

9. dellzasaur

@dpflan Yes that makes a lot of sense! I was doing the wrong thing at first adding the two numbers together and then subtracting them from 180. I see what I did wrong now. Thank you very much :) So basically if it's isosceles, I just subtract one measurement from 180 & then divide by 2 to get my answer?? I think that I probably could now!

10. campbell_st

you need to identify the base angles.... they are opposite the equal sides.... then work from there...

11. dellzasaur

@campbell_st oh okay :) thanks

12. dpflan

|dw:1343231097998:dw|

13. dpflan

|dw:1343231118772:dw|

14. dpflan

Yeah, sorry for the delay @dellzasaur - for the two sides that are the same length, the angles opposite the same length sides would be the ones for which, if you are given the angle of the different length side, you would subtract from 180 and divide by to 2 to obtain the degrees for the other angles. In the drawing, B and C are the angles that would be the same degree. S|dw:1343231278304:dw| So 180 - A = The Remaining Degrees. Then B=C=(The Remaining Degrees) / 2 Yeah, seems like you understand. Good luck with the rest

15. dellzasaur

@dpflan thank you so much for your help & the picture! Really helps me understand. I appreciate it