Question

identifying an unknown value
what is the value of x?
40
70
140
160

Explanation:

Step1: Identify triangle type

The triangle has two equal sides (marked with ticks), so it's isosceles. Thus, the two base angles are equal (let each be \( x \)).

Step2: Use triangle angle sum

The sum of angles in a triangle is \( 180^\circ \). So, \( 40^\circ + x + x = 180^\circ \).

Step3: Solve for \( x \)

Simplify: \( 40 + 2x = 180 \). Subtract 40: \( 2x = 140 \). Divide by 2: \( x = 70 \).

Answer:

70