The <em>missing</em> angle of the <em>right</em> triangle ABC has a measure of 30°. (Correct answer: A)
<h3>How to find a missing angle by triangle properties</h3>
Triangles are <em>geometrical</em> figures formed by three sides and whose sum of <em>internal</em> angles equals 180°. There are two kind of triangles existing in this question: (i) <em>Right</em> triangles, (ii) <em>Isosceles</em> triangles.
<em>Right</em> triangles are triangles which one of its angles equals 90° and <em>isosceles</em> triangles are triangles which two of its sides have <em>equal</em> measures.
According to the statement, we know that triangle BQR is an <em>isosceles</em> triangle, whereas triangles ABC, ANB and NBC are <em>right</em> triangles. Based on the figure attached below, we have the following system of <em>linear</em> equations based on <em>right</em> triangles ABC and NBC:
<em>2 · x + 90 + θ = 180</em> (1)
<em>(90 - x) + 90 + θ = 180</em> (2)
By equalizing (1) and (2) we solve the system for <em>x</em>:
<em>2 · x = 90 - x</em>
<em>3 · x = 90</em>
<em>x = 30</em>
And by (1) we solve the system for <em>θ</em>:
<em>θ = 180 - 2 · x - 90</em>
<em>θ = 30</em>
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The <em>missing</em> angle of the <em>right</em> triangle ABC has a measure of 30°. (Correct answer: A) 
To learn more on right triangles, we kindly invite to check this verified question: brainly.com/question/6322314
The correct answer would be C. The variable
Answer:
(-16.494 ; -3.506)
Step-by-step explanation:
student Prob A Prob B difference, d (A-B)
1 20 35____ - 15
2 30 40 ___ - 10
3 15 20 ___ - 5
4 40 50 __ - 10
Difference, d = -15, -10, -5, -10
Xd = Σd/ n = - 40 / 4 = - 10
Standard deviation of d ; Sd = 4.082
The confidence interval for the difference is given as :
Xd ± Tcritical*(Sd/√n)
Tcritical at 95%; df = n - 1 ; 4 - 1 = 3
Tcritical(0.05, 3)). = 3.182
C.I = -10 ± 3.182(4.082/√4)
C.I = -10 ± 6.494462
C. I = (-16.494 ; -3.506)
38.48 cm. This is so because the equation to find circumference is

R squared.
A² + b² = c²
3² + 6² = x²
x² = 9 + 36
x² = 45
x = √45
x = 3√5
Answer: x = 3√5