Question

Can someone please help me coz i really need this :(i need serious answer :(​

Answer 1

ANSWER:

[i] AC = 10, so DB = 10.

REASON:

Diagonal of isosceles trapezoid are equal.

ANSWER:

[ii] m∠DAB + m∠BCD = 180°

• m∠BCD = 180° – 120°
• m∠BCD = 60°

REASON:

If a quadrilateral is an isosceles trapezoid, the opposite angles are supplementary.

Answer 2

Answer:

1. DB = 10 as diagonals of isosceles trapezoid are congruent

2. ∠DAB and ∠BCD are supplementary angles

• m∠BCD = 180° - 120° = 60°

3. ∠BCD is congruent with ∠ADC as trapezoid is isosceles

• m∠BCD = m ∠ADC = 65°

4. AB = 15, DC = 25,

• EB = 1/2(AB + DC) as midline
• EB = 1/2(15 + 25) = 20

5. m∠ADC = 2x - 10, m∠ABC = 3x + 40

These are supplementary, find x first:

• 2x - 10 + 3x + 40 = 180
• 5x + 30 = 180
• 5x = 150
• x = 30

• m∠BCD = m∠ADC = 2*30 - 10 = 50°