A3. One of the angles of a triangle is $80^{\circ}$. One of the other two angles is $60^{\circ}$ more than the third angle. What type of triangle do I have?

Step 1 ：Given that one of the angles of a triangle is \(80^\circ\). One of the other two angles is \(60^\circ\) more than the third angle.

Step 2 ：The sum of the angles in a triangle is always \(180^\circ\). Let's denote the other two angles as \(x\) and \(y\), where \(x\) is \(y + 60^\circ\).

Step 3 ：We can set up the following system of equations to find the values of \(x\) and \(y\): \(x + y + 80 = 180\) and \(x = y + 60\)

Step 4 ：Solving this system of equations, we find that \(x = 80^\circ\) and \(y = 20^\circ\).

Step 5 ：This means the three angles of the triangle are \(80^\circ\), \(80^\circ\), and \(20^\circ\).

Step 6 ：A triangle with two equal angles is an isosceles triangle.

Step 7 ：Final Answer: The triangle is an \(\boxed{\text{isosceles triangle}}\).