Question

what is the ( mangle acb )?
( 10^{circ} )
( 50^{circ} )
( 90^{circ} )
( 180^{circ} )

Explanation:

Step1: Use triangle angle - sum property

In a right - triangle, the sum of the interior angles is \(180^{\circ}\). Given one angle is \(90^{\circ}\), and the other two angles are \((4x)^{\circ}\) and \((7x - 20)^{\circ}\). So, \(90+4x+(7x - 20)=180\).

Step2: Simplify the equation

$$
LATEXBLOCK0
$$

Step3: Find \(m\angle ACB\)

Substitute \(x = 10\) into \((7x - 20)^{\circ}\). Then \(7x-20=7\times10 - 20=70 - 20 = 50\)

Answer:

\(50^{\circ}\)