From the image, what is the value of angle LNMB?

In the bottom diagram, AB is the diameter of the circle. N and M are points on the circumference.

We are given LNBA = 73 degrees. This is an inscribed angle subtending arc NA.

Since AB is the diameter, the angle subtended by the diameter at any point on the circumference is 90 degrees. Therefore, angle ANB = 90 degrees.

In the right-angled triangle ANB, the sum of the other two angles is 90 degrees.

So, angle BAN + angle NBA = 90 degrees.

angle BAN + 73 degrees = 90 degrees.

angle BAN = 90 degrees - 73 degrees = 17 degrees.

The angle LNMB is an inscribed angle that subtends arc NB.

The inscribed angle that subtends the same arc NB is angle NAB (or BAN).

Therefore, LNMB = angle NAB.

LNMB = 17 degrees.

Ответ: 17°