Question

what is the value of angle b in the given figure below? o a. b = 25.5 o b. b = 26.5 o c. b = 25 o d. b = 26

Explanation:

Step1: Recall angle - sum property of a triangle

The sum of the interior angles of a triangle is 180°. In a right - triangle, one angle is 90°.

Step2: Set up the equation

Let the three angles of the triangle be 90°, 39°, and 2b°. Then 90 + 39+2b=180.

Step3: Simplify the left - hand side of the equation

129 + 2b=180.

Step4: Isolate the variable term

Subtract 129 from both sides: 2b=180 - 129.
2b = 51.

Step5: Solve for b

Divide both sides by 2: b=\frac{51}{2}=25.5.

Answer:

A. b = 25.5