∠C and ∠D are a linear pair. ∠C is four times larger than ∠D. What is the measure of ∠C?

first we represent the unknowns using variables:

let x = measure of angle 4

let 3x+4 = measure of angle 3 (from the second statement)

then we set-up the equation. since the angles form a linear pair, their sum is equal to 180 degrees. therefore,

x + 3x + 4 = 180

4x + 4 = 180

4x = 176

x = 44 degrees (measure of angle 4)

3x + 4 = 136 degrees (measure of angle 3)

yes

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