Question

11. The angles of a triangle are (x + 21)°, x° and (2x – 45)”. Find the value of x.​

Answer 1

Answer:

Angle sum property of a triangle = $180°$

$x+21 + x + (2x-45) = 180°$

$2x + 21 + 2x - 45 = 180°$

$4x - 24 = 180°$

$4(x - 6) = 180°$

$x - 6 = \large{\frac{180°}{4 }}$

$x-6 = 45$

$x = 45 + 6$

$\bold{x= 51°}$

$Therefore,$ $\large\underline\bold{x = 51°}$

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Extra~

$(x + 21) = 51 + 21 = 72°$

$(2x - 45) = 2 × 51 - 45 = 102 - 45 = 57°$

Angles of triangle are 51°, 57° and 72°.

$Hope\;this\;Helps:)$