12. Find the value of x.
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Answer:
x = 16
Step-by-step explanation:
SR = ST ⇒ Two sides are equal. So, ΔSRT is an isosceles triangle.
The angles opposite to equal sides are equal.
⇒ ∠STR = ∠R
∠STR = 4x - 28
Linear pair: If a ray stands on a line, then the adjacent angles are supplementary and they are called linear pair
∠STR + ∠STU = 180° {linear pair}
4x - 28 + 9x = 180
4x + 9x - 28 = 180 {Combine like terms}
13x- 28 = 180
Add 28 to both the sides
13x = 180 + 28
13x = 208
Divide both sides by 13
x = 208/13
[tex]\sf \boxed{x = 16}[/tex]
Answer:
x = 16
Step-by-step explanation:
since SR = ST , then Δ RST is isosceles with the 2 base angles congruent.
∠ STR = ∠ SRT = 4x - 28
∠ STR and ∠ STU are a linear pair and sum to 180° , that is
9x + 4x - 28 = 180
13x - 28 = 180 ( add 28 to both sides )
13x = 208 ( divide both sides by 13 )
x = 16