If A = (25x + 1) °, C = (25x - 2) ° and D = (20x - 1) °, find D.

We are asked to find the angle D given that we have the three angles of a triangle and we also know that the summation of all angles in a triangle is equal to 180°. Thus, the solution to this problem is shown below:

∠A = (25X + 1) °

∠C = (25X - 2) °

∠D = (20X - 1) °

180° = (25X + 1) ° + (25X - 2) ° + (20X - 1) °

180° = 25X + 1+25X - 2 + 20X - 1

180° = 70X - 2

180° + 2 = 70X

182/70 = 70X / 70

2.6 = X

Since we already know that the value for x is equal to 2.6, we can now solve for D such as the solution is shown below:

∠D = 20x - 1

∠D = (20*2.6) - 1

∠D = 51°

The answer for the value of D is equal to 51°.