Answer:
l=0.1401P\\
w =0.2801P
where P = perimeter
Step-by-step explanation:
Given that a window is in the form of a rectangle surmounted by a semicircle.
Perimeter of window =2l+\pid/2+w

Or 
To allow maximum light we must have maximum area
Area = area of rectangle + area of semi circle where rectangle width = diameter of semi circle


Hence we get maximum area when i derivative is 0
i.e. 

Dimensions can be

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
C= .85p
Shipping 2 lbs is $1.80
C=.80p