EXPLANATION
M13. Find the missing angle in a triangle with angles measuring 40° and 80°.
a) 20°
b) 40°
c) 60°
d) 100°
ANSWER: c) 60°
EXPLANATION:
To find the missing angle in a triangle, we can use the fact that the sum of the angles in a triangle is always 180 degrees.
Let's denote the missing angle as x. We have the given angles as 40° and 80°. Adding these two angles, we get:
40° + 80° + x = 180°.
Combining like terms, we have:
120° + x = 180°.
Now, we can isolate x by subtracting 120° from both sides of the equation:
x = 180° - 120° = 60°.
Therefore, the missing angle in the triangle is 60°.
So, the correct option is:
c) 60°.
