Find the measure of angle A

Explanation:

The three angles of this triangle are

The square angle marker represents 90 degrees. It's also referred to as "a right angle".

As a rule, the three angles of any triangle always add to 180. Let's use this fact to solve for x

(angle1)+(angle2)+(angle3) = 180

(20x)+(90)+(26x-2) = 180

(20x+26x) + (90-2) = 180

46x+88 = 180

46x = 180 - 88 subtract 88 from both sides

46x = 92

x = 92/46 divide both sides by 46

x = 2

Now that we know what x is, we can find angle A

angle A = 20x = 20*2 = 40 degrees

As extra info, we could also find the other angle with this x value

26x - 2 = 26*2 - 2 = 52 - 2 = 50 degrees

The three angles of the triangle are: 40, 50, 90 which add to 40+50+90 = 180. This helps confirm our answer.