15: the red tiles are triangle, blue tiles are pentagons
<u>Part 1) </u>To find the measure of ∠A in ∆ABC, use
we know that
In the triangle ABC
Applying the law of sines

in this problem we have

therefore
<u>the answer Part 1) is</u>
Law of Sines
<u>Part 2) </u>To find the length of side HI in ∆HIG, use
we know that
In the triangle HIG
Applying the law of cosines

In this problem we have
g=HI
G=angle Beta
substitute


therefore
<u>the answer Part 2) is</u>
Law of Cosines
<h3>
<u>Answer</u><u>:</u></h3>

<h3>
<u>Explan</u><u>ation</u><u>:</u></h3>
First, convert any mixed numbers to fractions. An easy way to convert:

<h3>
=</h3>

Then, apply the fractions formula for division.

Then, simplify.
