Question 697592
Since side CA is adjacent to angle A and side AB is the hypotenuse. The Trig functions that have adjacent and hypotenuse in their ratios are cos and sec. Since our calculators probably do not have a sec button we will use cos:
{{{cos(55) = 10/x}}} where x is the length of side AB
Multiplying each side be x we can eliminate the fraction:
{{{x*cos(55) = 10}}}
Dividing each side by cos(55):
{{{x = 10/cos(55)}}}
This is an exact expression for the solution. For a decimal approximation we use our calculators to divide 10 by cos(55):
{{{x = 10/0.57357643635104609610803191282616}}}
{{{x = 17.434467956210980198376834167244}}}
Rounded to the nearest integer this would be 17.