Ellie was constructing an isosceles right triangle. He is provided with the measure of the base of the triangle. His first step was to use a ruler to draw the base of the triangle, and his next step was to use a protractor to draw one of the base angles. What should his next step be?A.)Use a protractor to construct a 45° base angle.B.)Use a ruler to draw the first leg of the triangle.C.)Use a ruler to draw the second leg of the triangle.D.)Use a protractor to draw a right angle.

first step: use a ruler to draw the base of the triangle.
The base of an isosceles triangle represents the hypotenuse of the right triangle.

second step: was to use a protractor to draw one of the base angles.

For an isosceles right triangle the each of base angels will be equal 45°

So, the next step ⇒⇒ Use a protractor to construct a 45° base angle.

The correct choice is option (A)

 A.)Use a protractor to construct a 45° base angle.