Answer:
43.8°
Step-by-step explanation:
Applying,
Cosine rule,
From the diagram attached,
x² = y²+z²-2yxcos∅.................... Equation 1
where ∅ = ∠YXZ
Given: x = 8.7 m, y = 10.4 m, z = 12.4 m
Substitute these values into equation 1
8.7² = 10.4²+12.4²-[2×10.4×12.4cos∅]
75.69 = (108.16+153.76)-(257.92cos∅)
75.69 = 261.92-257.92cos∅
collect like terms
257.92cos∅ = 261.92-75.69
257.92cos∅ = 186.23
Divide both sides by the coefficient of cos∅
cos∅ = 186.23/257.92
cos∅ = 0.722
Find the cos⁻¹ of both side.
∅ = cos⁻¹(0.7220)
∅ = 43.78°
∅ = 43.8°
Answer:

Step-by-step explanation:

Hope this helps!
True the circle is a congruent to the radius of an inscribed regular polygon inside the circle
Answer:
C is correct
Step-by-step explanation: c is correct great job
Answer: 17 -3n
Explanation:
In the given arithmetic progression 20,17,14,11,8....
first term that is a = 20
common difference that is d= a2-a1 = 17-20 = -3
let n is the nth term
= a+(n-1)d
substituting the values of first, common,difference and n
=20+(n-1) (-3)
= 20 -3n+3
=23 -3n