Answer: The measure of angle 1 is 39 degrees,the measure of angle 2 is 78 degrees and the measure of angle 3 is 63 degrees.
Step-by-step explanation:
We will represent the measure of angle 1 by x because it is unknown.
It says that the measure of angle 2 is twice angle 1 so we could represent that as 2x and the measure of angle 2 is 15 less than angle 3 and we could also represent that by 2x - 15.
Now we know they all add up to 180 so add them up and set them equal to 180 and solve for x.
x + 2x + 2x -15 = 180
5x - 15 = 180
+15 +15
5x = 195
x = 39
If x is equal to 39 then the measure of angle 1 is 39 degrees and the measure of angle 2 is twice that so 2(39) = 78 which also gives us the measure of angle 2 as 78.
For angle 3 it says that it has to be 15 less than the measure of angle so subtract 15 from 78 to find the measure of angle 3.
78 - 15 = 63 The measure angle 3 is 63 degrees. Now add the measures all together to see if they equal 180 degrees .
Check:
39 + 78 + 63 = 180
180 = 180
