Question

Can someone please explain
how to do this

Answer 1

the answer is 93°

Explanation:

As you know that in a triangle,

angle1+angle2+angle3 = 180°

hence,

angle ABC + angle BAC + angle DCB + angle ACD ( Angle DCB + angle ACD = angle BCA) = 180°

75°+51°+2x+1x (let the ratio be x) = 180°

126°+3x = 180°

3x = 54°

x = 18°

2x = 36° = angle DCB

In triangle DCB,

51°+36°+angle BCD = 180°

angle BCD = 180°- 87°

Hence, angle BCD = 93°

Answer 2

93

Explanation:

A + B +C = 180

75+51 + C =180

126 +C =180

C = 180-126 = 54

DCB : ACD = 2:1

DCB = 2x

ACD = x

2x+x=54

3x = 54 ; x = 54/3 = 18

DCB = 2x = 2 x 18 = 36

dcb + dbc + bdc = 180

51 + 36 + bdc = 180

87 + bdc = 180 ; bdc = 180 - 87 = 93

I hope im right!!