This is a triangle with one known angle of 100° at the top and two identical angles labeled as $x^\circ$.

In any triangle, the sum of all three angles is always 180°. Thus, we can set up the following equation to solve for $x$:

$100^\circ + x^\circ + x^\circ = 180^\circ$

Simplifying the equation:

$100^\circ + 2x = 180^\circ$

Subtract 100° from both sides:

$2x = 80^\circ$

Now, divide by 2:

$x = 40^\circ$

So, each of the unknown angles is $40^\circ$.

Would you like more details or have any questions? Here are five related questions to consider:

1. What is the sum of the interior angles in a quadrilateral?
2. How can you prove that the sum of the angles in a triangle is always 180°?
3. What is an isosceles triangle, and how does it relate to this problem?
4. Can you apply the same approach to find angles in an obtuse triangle?
5. How does the exterior angle of a triangle relate to its interior opposite angles?

Tip: Always remember, the sum of the angles in any triangle is 180°, a fundamental rule in geometry!