SAT Question 145337bc: Right Triangles And Trigonometry answer and explanation with Desmos solution

Choice A is correct. Since the two acute angles have the same measure and the third angle is a right angle, the triangle shown is an isosceles right triangle. In an isosceles right triangle, the two legs have the same length. The figure shows that the length of one leg of the triangle is $24$ and the length of the other leg of the triangle is $x$. It follows that the value of $x$ is $24$.