Question

Please helppppp meeeeeee!!!!!!!!!!!!!!!!!!!!

Answer 1

The option is C i.e 115°, 65°. proof is given below.

Explanation:

Given:

ABCD is a quadrilateral.

m∠ A = 100 + 5x

m∠ B = 77 - 4y

m∠ C = 106 + 3x

m∠ D = 47 + 6y

To Prove:

ABCD is a parallelogram if opposing angles are congruent by finding the measures of angles.

m∠ A = m∠ C and

m∠ B = m∠ D

Proof:

ABCD is a quadrilateral and is a parallelogram if opposing angles are congruent.

∴ m∠ A = m∠ C

On substituting the given values we get

∴ 100 + 5x = 106 +3x

∴
`5x-3x=106-100\\\\2x=6\\\\x =(6)/(2) \\\\x=3`

m∠ A = 100 + 5x = 100 + 5 × 3 =100 + 15 = 115°

m∠ C = 106 + 3x = 106 + 3 ×3 =106 + 9 = 115°

∴ m∠ A = m∠ C = 115°

Similarly,

∴ m∠ B = m∠ D

77 - 4y = 47 + 6y

10y = 77 - 47

10y =30

∴
`y=(30)/(10) \\y = 3\\`

m∠ B = 77 - 4y =77 - 4 × 3 = 77 - 12 = 65°

m∠ D = 47 + 6y = 47 + 6 × 3 = 47 + 18 = 65°

∴ m∠ B = m∠ D = 65°

Therefore the option is C i.e 115°, 65°