Triangle DEF has interior angles at D and E, which measure 100 and 25. What is the measure of the
exterior angle at F?
F = 180-100-25 = 55o.
Ext. angle = 180-55 = 125o.
In a triangle, the sum of all interior angles is always 180 degrees.
Given that angle D measures 100 degrees and angle E measures 25 degrees, we can find the measure of angle F by subtracting the sum of angles D and E from 180 degrees.
180 degrees - 100 degrees - 25 degrees = 55 degrees
Therefore, the measure of the exterior angle at F is 55 degrees.
To find the measure of the exterior angle at F, we need to know the sum of the measures of the interior angles of a triangle, which is always 180 degrees.
In this case, we are given that angle D measures 100 degrees and angle E measures 25 degrees.
To find the measure of angle F, we can subtract the sum of angles D and E from 180 degrees.
180 - (100 + 25) = 180 - 125 = 55
So, the measure of the exterior angle at F is 55 degrees.