Answer:
Isosceles right triangle.
Step-by-step explanation:
From the given triangle ABM,
AM ≅ MB [Given]
∠AMB is an angle subtended by the diameter AB.
By theorem, angle subtended by a diameter is always 90°.
m∠AMB = 90°
So the given triangle is a right triangle with two equal sides AM and MB.
Therefore, ΔAMB is an isosceles right triangle.