Answer:
If cos(E) = sin(F), then we know that m∠E + m∠F = 90 degrees (since E and F are acute angles).
We are given that m∠E = (8x - 12) degrees, and we want to find m∠F.
We can substitute the given value of m∠E into the equation m∠E + m∠F = 90 degrees, and solve for m∠F:
(8x - 12) + m∠F = 90
m∠F = 78 - 8x
So the measure of angle F is 78 - 8x degrees.
We are also given that m∠F = (6x - 10) degrees. So we can substitute this value into the equation we just found:
m∠F = (6x - 10) = 78 - 8x
We can now solve this equation for x:
6x - 10 = 78 - 8x
14x = 88
x = 6
So we know that x = 6.
Now we can substitute this value back into the equation m∠F = (6x - 10) to find the measure of angle F:
m∠F = (6x - 10) = (6 * 6) - 10 = 24 degrees
So the measure of angle F is 24 degrees.