An angle measures 51 degrees. What is the measure of its supplement?

so the supplement is 129 right?

an angle and its supplement sum to 180º

yup

An angle measures 51 what is the measure of its supplement

To find the measure of the supplement of an angle, we need to know that the supplement of an angle is 180 degrees minus the measure of the angle. In this case, the given angle measures 51 degrees. So, to find the measure of the supplement:

Supplement of the given angle = 180 degrees - measure of the given angle

Substituting the value given:

Supplement of the given angle = 180 degrees - 51 degrees

Calculating:

Supplement of the given angle = 129 degrees

Therefore, the measure of the supplement of the angle measuring 51 degrees is 129 degrees.