\(5sin(46)\)
This is a trig problem that cannot be done in your head because it is not one of the easy angles to remember. The only way to find the answer is to use a calculator that has trig functions.
To solve the trig problem, first find out what \(sin(46)\) is by putting that in your calculator. When you do that you get \(sin(46)=0.901788347649\)
Next multiply 5 to that answer and when you do you get \(4.508941738245\)
Because the answer is a long decimal number, usually you would round the answer to the nearest tenth or hundredth and when you do that the answer is either \(4.5\) or \(4.51\)
Hope this helps.