Question

Calculate the value of $x:$

Answer 1

(a) straight line

$\Rightarrow 2x+3x={180}^{\circ }$

$5x={180}^{\circ }$

$x={36}^{\circ }$

(b) Right angle

$\Rightarrow 5x+4x={90}^{\circ }$

$9x={90}^{\circ }$

$x=10$

$\left(c\right)2x+x+4x+3x={360}^{\circ }$

$10x={360}^{\circ }$

$x=36$

$\left(d\right)3x-5+x+20+{65}^{\circ }={180}^{\circ }$

$4x+80={180}^{\circ }$

$4x=100$

$x=25$

$\left(e\right)2x+x+60+2x=360$

$5x=300$

$x={60}^{\circ }$