408,029 views
27 votes
27 votes
Can someone please help me coz i really need this :(

i need serious answer :(​

Can someone please help me coz i really need this :( i need serious answer :(​-example-1
User Choldgraf
by
3.3k points

1 Answer

16 votes
16 votes

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°
User Robertly
by
3.4k points