Write the algebraic expression described.
-The sum of the angles of a triangle is 180°. If one angle of a triangle measures x° and a second angle measures (4x + 20)°, express the measure of the third angle in terms of x.
A)(200 - 5x)°
B)(160 - 4x)°
C)(160 - 5x)°
D)(160 + 5x)°

Question

Quizplus · Accepted Answer

The sum of the three angles in a triangle is 180°. Let the measure of the third angle be y°. Then, we can write the equation:
x + (4x + 20) + y = 180
Simplifying and solving for y, we get:
y = 160 - 5x
Therefore, the measure of the third angle is (160 - 5x)°, which corresponds to choice C. The sum of the three angles in any triangle is 180°. Therefore, we can write an equation using the given information:
x + (4x + 20) + third angle = 180
Simplifying this equation, we get:
5x + 20 + third angle = 180
third angle = 180 - 5x - 20
third angle = 160 - 5x
Thus, the measure of the third angle in terms of x is (160 - 5x)°, which is choice (C).

Write the Algebraic Expression Described