Find the value of x in the isosceles triangle shown below

x = 12

Step-by-step explanation:

Since the 2 legs and base angles are congruent the triangle is isosceles.

The line from the vertex to the base is a perpendicular bisector dividing the triangle into  2 right triangles.

Using Pythagoras' identity in either of the 2 right triangles with legs 3 and x , hypotenuse , then

( x )² + 3² = ( )²

x² + 9 = 45 ( subtract 9 from both sides ²)

x² = 36 ( multiply both sides by 4 to clear the fraction )

x² = 144 ( take the square root of both sides )

x = = 12

2/3

step-by-step explanation:

the slope of a line is equal to the rise/run. in this case the line rises 2 units for every +3 units it moves

second option

step-by-step explanation:

the measures of a triangle equal 180. use that to find x.

2x+3x+4x=180

9x=180

9x/9=180/9

x=20

now you know x, you know angle a is 40°, angle b is 60°, angle c is 80°.

because angle a is 40°, the first option doesn't work.

because angle b is 60°, the second option does work.

when you add angle a and b, you get 100°. complementary means it equals 90°, so the third option doesn't work.

when you add angle a and c, you get 120°, which is not 100.