Here you go the answer for the question
Answer:
13 cm
Step-by-step explanation:
Use Pythagora's theorem to solve for the hypotenuse of the triangle:
![a^2+b^2=c^2](https://tex.z-dn.net/?f=a%5E2%2Bb%5E2%3Dc%5E2)
Where a and b are the two shorter legs, and c is the hypotenuse.
Replace the values in and solve for c:
![5^2+12^2=c^2\\25+144=c^2\\169=c^2\\13=c](https://tex.z-dn.net/?f=5%5E2%2B12%5E2%3Dc%5E2%5C%5C25%2B144%3Dc%5E2%5C%5C169%3Dc%5E2%5C%5C13%3Dc)
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>
<em />
The <em>missing</em> angle of the <em>right</em> triangle ABC has a measure of 30°. (Correct answer: A) ![\blacksquare](https://tex.z-dn.net/?f=%5Cblacksquare)
To learn more on right triangles, we kindly invite to check this verified question: brainly.com/question/6322314
The area of the base (six triangles with a base 15m and a height 7.5√3m):
![A_B=6\cdot\dfrac{1}{2}\cdot15\cdot7.5\sqrt3\approx585\ m^2](https://tex.z-dn.net/?f=A_B%3D6%5Ccdot%5Cdfrac%7B1%7D%7B2%7D%5Ccdot15%5Ccdot7.5%5Csqrt3%5Capprox585%5C%20m%5E2)
The area of side walls (six triangles with a base 15m and a height 12m)
![A_W=6\cdot\dfrac{1}{2}\cdot15\cdot12=540\ m^2](https://tex.z-dn.net/?f=A_W%3D6%5Ccdot%5Cdfrac%7B1%7D%7B2%7D%5Ccdot15%5Ccdot12%3D540%5C%20m%5E2)
The surface area:
Answer:
-3
Step-by-step explanation:
-1 -2 = -3