The triangle in your image appears to be isosceles, given that two sides are marked as equal. One of the angles is labeled as 58°, and you are likely looking to find the unknown angle.

Here’s how to approach this:

1. In an isosceles triangle, the base angles (the angles opposite the equal sides) are equal. The angle of 58° is likely the vertex angle between the two equal sides.

2. The sum of angles in any triangle is always 180°. So, let’s set up the equation: $\text{Let each of the unknown base angles be } x.$ $58^\circ + 2x = 180^\circ$ Solving for $x$: $2x = 180^\circ - 58^\circ = 122^\circ$ $x = \frac{122^\circ}{2} = 61^\circ$

Therefore, each of the base angles is 61°.

Would you like any further explanation on this? Here are a few related questions to expand on this concept:

1. What is the general property of angles in any triangle?
2. How can you prove that the base angles in an isosceles triangle are equal?
3. How would you solve a similar problem for an equilateral triangle?
4. How do you calculate exterior angles in a triangle?
5. How does the Pythagorean theorem apply to right-angled triangles?

Tip: In any triangle, the sum of the three interior angles is always 180°.