okay so
117° + angle a = 180° (supplementary angle)
angle a = 180 - 117
= 63°
then angle a + angle b + 81° = 180° ( angle sum property)
so... 63° + angle b + 81° = 180
144 + angle b = 180°
angle b = 180 - 144
= 36°
hope this helps.
ANSWER
The length of a Diameter is 3.714
EXPLANATION
The circumscribed triangle is shown in the attachment.
We use the cosine ratio to find the altitude of the isosceles triangle.


Altitude =8cos(60°)
Altitude=4cm
Let the upper half of the altitude be y cm.
Then the radius of the circle is (y-4)cm
The upper radius meets the tangent at right angles.
From the smaller right triangle,






y=1.857
The diameter is 2y

=2(1.875)
The length of a Diameter is 3.714
Answer:
Each student would get 4 inches of ribbon
Step-by-step explanation:
Mrs. Barkley has 75 inches of ribbon and is splitting it between 18 students so you would divide 75 by 18. When you divide you get 4.166666... etc. So the answer would be 4