Question

In ARST, r = 1.7 inches, s = 7.3 inches and ZT=15°. Find the length of t, to the nearest

10th of an inch.

Answer 1

The answer is "5.7"

Explanation:

Using the cosine rule.

`\cos T = (r^2+s^2-t^2)/(2rs) \\\\t^2= r^2+s^2-2rs \cos T ........(i)\\\\r=1.7\\s=7.3\\T=15\\\\t^2= (1.7)^2+(7.3)^2-2(1.7)(7.3) \cos 15^(\circ) \\\\`

`=2.89+53.29-24.82(0.9659)\\\\=32.2064`

`t= 5.6751 =5.7`