Question

find missing angles quick check
there are angles whose measures add to 180°. their measures are: ( mangle a = 67^circ ), ( mangle b = (2x + 39)^circ ) and ( mangle c = x^circ ). what is the measure of ( angle b )? (1 point)
options: ( 82^circ ), ( 180^circ ), ( 62^circ ), ( 31^circ )

Explanation:

Step1: Set up angle sum equation

$67 + (2x + 20) + x = 180$

Step2: Simplify the left side

$3x + 87 = 180$

Step3: Solve for $x$

$3x = 180 - 87 = 93$
$x = \frac{93}{3} = 31$

Step4: Calculate $m\angle B$

$m\angle B = 2(31) + 20 = 82$

Answer:

82°