Question

find the value of x
o a. 68 degrees
o b. 72
o c. 75
o d. 65
o e. 65 degrees
o f. 70 degrees
o g. 90 degrees
o h. 180 degrees

Explanation:

Step1: Recall triangle - angle sum property

The sum of the interior angles of a triangle is 180°. Also, the triangle is isosceles (indicated by the equal - side markings), so the two base angles are equal. Let the base angles be \(x\).

Step2: Set up an equation

We know that \(40^{\circ}+x + x=180^{\circ}\), which simplifies to \(40^{\circ}+2x = 180^{\circ}\).

Step3: Solve the equation for \(x\)

First, subtract 40° from both sides: \(2x=180^{\circ}- 40^{\circ}=140^{\circ}\). Then divide both sides by 2: \(x=\frac{140^{\circ}}{2}=70^{\circ}\).

Answer:

F. 70 degrees