Answer:
x = 63.9
Step-by-step explanation:
We have:
[tex]\frac{QR}{sin35}[/tex] = [tex]\frac{78}{sin90}[/tex]
=> QR × sin90 = 78 × sin35
=> QR × sin90 = 44.7
=> QR = 44.7
But, we also have: [tex]x^{2}[/tex] + [tex]QR^{2}[/tex] = [tex]78^{2}[/tex] <=> [tex]x^{2}[/tex] + [tex]44.7^{2}[/tex] = [tex]78^{2}[/tex] <=> [tex]x^{2}[/tex] = 6084 - 1998.09
=> [tex]x^{2}[/tex] = 4085.91
=> x = [tex]\sqrt{4085.91}[/tex] = 63.9211.. = 63.9
<3 Have a nice day!!
