Question

which of the following figures has an∠abc of 90°? select an answer:

Explanation:

Step1: Recall the theorem

The angle inscribed in a semi - circle is a right - angle. That is, if an angle $\angle ABC$ is inscribed in a semi - circle with diameter $AC$, then $\angle ABC = 90^{\circ}$.

Step2: Analyze the figures

We need to find the figure where points $A$, $B$, and $C$ are on the circle and $AC$ is the diameter of the circle. In the second figure, $AC$ is the diameter of the circle and $\angle ABC$ is an inscribed angle subtended by the diameter $AC$.

Answer:

The second figure.