16 I believe not 100% sure though
Answer:
90°
Step-by-step explanation:
Let there measures of the angles of a triangle are 2x, 2x and 4x.
We know that the sum of angles of a triangle is equal to 180°. So,
2x+2x+4x=180
8x=180
x = 22.5
We know that, the measure of an exterior angle of a triangle is equal to the sum of the measures of the two non-adjacent interior angles.
So, the exterior angle = 4x = 4(22.5) = 90°
Answer:
Sol1 you can use "first(first+last)/2" is 138(138+1)/2 - 38(38+1)/2 = 8850
Sol2 or you can look this 39+40+41+....+100+(100+1)+(100+2)+....+(100+38) = 1+2+3+.....+99+100+100(38) = 5050+3800 =8850
