Question: Finding value of x

Finding value of x

so im supposed to find the value of x in an isosceles triangle (4x-20) is the degree at the bottom of the triangle and then at the right point of the triangle it says 3x degrees. And i have no idea on what i am supposed to be doing.

Date Posted: September 25, 2007 Tagged Under: geometry
Rating:
n/a

Does it look like this, where the 3x is at the top of the triangle and the 4x-20 is at the bottom left...

or is the 3x at the bottom right angle?

Rating:
10.0

If these assumptions are correct this is how you get to the answer:

an isosceles triangle has two congruent sides and therefor two congruent angles.

so you have all three angles in terms of x and you know that three angle of a triangle equal 180 degrees so you need to set up the following equation:

(4x-20) + (4x-20) + 3x = 180
solve for x to get 4x-20+4x-20+3x = 180
combine terms to get 11x-40=180
solve for x to get 11x=220 or x=20

if you plug x into each of the equations you get that all the angles are 60 degrees making it an equilateral triangle.

Rating:
9.0

I am trying to visualize the triangle and what information you have. If you draw a triangle, they are giving you (4x-20) for one angle and (3x) for the other angle and that is all the information they give? Just wanted to make sure I understand the question before I work on it.