Question

Suppose point D is in the interior of ∠ABC

Answer 1

Answer:

$ABC = 130$

Step-by-step explanation:

Given

$ABC=12x - 110$

$ABD=3x+40$

$DBC=2x - 10$

Required

Determine the measure of ABC --- Missing part of the question

First, we need to determine the value of x

Since, D is an interior of ABC, then

$ABC = ABD + DBC$

$12x - 110 = 3x + 40 + 2x - 10$

Collect Like Terms

$12x - 3x - 2x = 110 + 40 - 10$

$7x = 140$

Solve for x

$x = 140/7$

$x = 20$

Substitute 20 for x in $ABC=12x - 110$

$ABC = 12 * 20 - 110$

$ABC = 240 - 110$

$ABC = 130$