Question

1.) What is m ABC?
Show your work.
75
135
с

Answer 1

Answer:

$\angle ABC =60$

Step-by-step explanation:

Given

$\angle CAB = 75$

The attached triangle

Required

Find $\angle ABC$

First, calculate $\angle BCA$

$\angle BCA + 135 = 180$ --- angle on a straight line

$\angle BCA = 180 - 135$

$\angle BCA = 45$

$\angle ABC$ is then calculated using:

$\angle ABC + \angle BCA + \angle CAB =180$ -- angle in a triangle

$\angle ABC + 45+ 75=180$

$\angle ABC =- 45- 75+180$

$\angle ABC =60$