Question

the diagram shows a triangle.

what is the value of x?

x = \boxed{\circ}

submit

Explanation:

Step1: Sum angles to 180°

$(4x-21)+(2x+12)+(5x+13) = 180$

Step2: Combine like terms

$4x+2x+5x -21+12+13 = 180$
$11x + 4 = 180$

Step3: Isolate the variable term

$11x = 180 - 4$
$11x = 176$

Step4: Solve for x

$x = \frac{176}{11}$

Answer:

$16$