Question

in the given figure, find the value of ∠A.​

Answer 1

Answer:

Sum of all measures of triangle is 180°.

$\therefore \: 5x - 60 + 2x + 40 + 3x - 80 = 180$

$\sf\: 5x + 2x + 3x - 60 + 40 - 80 = 180$

$\sf \therefore= 10x - 100 = 180$

$\sf \therefore \: 10 x= 180 + 100$

$\sf \therefore \: 10x = 280$

$\displaystyle \sf\therefore \: x = \frac{280}{10}$

$\sf \green{ \therefore \: x = 28}$

To find angle A :

Substitute value of x = 28 in 5x- 60, we get

$\sf\therefore \: 5(28) - 60$

$\sf \therefore \angle \: A \: = 140 - 60$

$\sf \therefore \angle \: A = 80{^ \circ}$