Respuesta :

Since this triangle is a isosceles triangle, meaning that two sides and angles are alike and one is not. You can assume that x is equal to the angle that is also not shown.

A triangle has a total of 180 degrees so I would subtract 38 to 180 like this

180 - 38 = 142

The two angles added together that we don't know yet is 142 degrees (if you add it together)

Divide 142 by 2 to get the value of x

142/2 = 71 degrees

x = 71

We know that this is true because:

71 + 71 + 38 = 180 degrees

If you drop a vertical line thru the 38-degree angle, you subdivide that angle into two equal angles of 19 degrees each.  You have a 90-degree angle where this vertical line intersects the base.

Recall that the sum of all the interior angles of a triangle is 180 degrees.  If you subtract the sum of 19 degrees and 90 degrees from 180 degrees, you'll have a value for x:


180 deg - (109 deg) = 71 deg.

x = 71 degrees.

Another way in which you could find x would be to write the equation

x + x + 38 = 180, or 2x = 142, or x = 71.  Again, x = 71 degrees.