Question

triangle f is a scaled copy of triangle e. what is the value of d?

Explanation:

Step1: Use the triangle angle sum property

The sum of angles in a triangle is \(180^{\circ}\).

Step2: Calculate the value of \(d\)

For triangle \(E\), we have \(21^{\circ}+21^{\circ}+138^{\circ} = 180^{\circ}\). Since triangle \(F\) is a scaled - copy of triangle \(E\), corresponding angles are equal. So \(d = 138\)

Answer:

\(138\)