7 is the value of x, and 64° is the measure of the unknown angle.
Triangle angles of 76°, (9x+1)°, and 40° are provided.
According to the triangle's "angle sum property," a triangle's angles add up to 180 degrees. Three sides and three angles, one at each vertex, make up a triangle. The sum of the interior angles in a triangle is always 180o, regardless of whether it is acute, obtuse, or right.
One of the most commonly applied properties in geometry is the triangle's angle sum property. Most often, the unknown angles are calculated using this attribute.
Now, the total of a triangle's three angles equals
76°+(9x+1)°+40°= 180°
⇒ 116+9x+1 = 180
⇒ 9x + 117 = 180
⇒ 9x = 63
⇒ x = 7
So, 9x+1=64°
As a result, x is equal to 7 and the unmeasured angle is 64°.
To learn more about the angle sum property of a triangle, refer to this link:
brainly.com/question/8492819
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