Question

Find ∠ABD if ∠ABC = 121° in the given figure.

Answer 1

81°

Explanation:

∠ABC= 121°

• 4x+21+3x-5=121
• 7x+16=121
• 7x= 105
• x=105/7
• x=15°

∠ABD= 4*15°+21°= 81°

Answer 2

81

Explanation:

ABD + BDC = ABC

4x+21 + 3x-5 =121

Combine like terms

7x +16 = 121

Subtract 16 from each side

7x+16-16 = 121-16

7x =105

Divide each side by 7

7x/7 =105/7

x=15

We want to find ABD

ABD = 4x+21

= 4*15+21

= 60+21

=81