Question

Find the value of x
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Answer 1

ANSWER = x = 50 , 3x = 150 , 130

if the number of sides is n then sum of internal angles

if the number of sides is n then sum of internal angles = ( n - 2) × 180

= ( 5- 2) × 180

= 3 × 180

= 540°

since x and other angle are linear pairs

other angle = 180 - x [ sum of linear pair =180]

80° + 90 + 90 + 3x + (180 - x ) = 540

260 ° + 180 ° + 3x - x = 540

440° + 2x = 540

2x = 540 - 440

= 100

x = 50°

3x = 3 × 50

= 150 °

180 - x = 180 - 50

= 130°