Find the area of a circle that has a radius of 19 centimeters

In trapezoid efgh, m∠hef=(4x2+16)∘ and m∠gfe=(5x2+12)∘. find the value of x so that efgh is isosceles.

What is the value of the expression i 0 × i 1 × i 2 × i 3 × i 4? 1 –1 i –i

Janice determined there were 10 possible outcomes when tossing two coins and spinning a spinner numbered 1 through 6. what is the correct number? what might have been janice's error?