Question

the diagram shows a triangle.
one angle is 4u, one is 84°, one is 60°.
what is the value of u?
u = \square°

Explanation:

Step1: Sum triangle angles to 180°

$4u + 60 + 84 = 180$

Step2: Simplify the left side

$4u + 144 = 180$

Step3: Isolate the term with $u$

$4u = 180 - 144$
$4u = 36$

Step4: Solve for $u$

$u = \frac{36}{4}$

Answer:

$u = 9$°