Answer: 2/4 simplified to 1/2
Step-by-step explanation:
Add the two angles and then subtract from 180* to find the missing angle
So,
145* + 15* = 160*
180* - 160* = 20*
Answer: x = 20*
The tangent half angle formula, one of several, is

We have θ is opposite 4 in the 3/4/5 right triangle so



Answer: 1/2
This is actually pretty deep. It says half the big acute angle in the 3/4/5 triangle is the small diagonal angle of the 1x2 rectangle. Similarly, the small acute angle in 3/4/5 triangle is twice the small diagonal angle of the 1x3 rectangle.
The answer would be the first one or the second one but I think it’s the x over 3
The answer is -.2.5 hope that help