Answer: 3/16
Step-by-step explanation: To multiply fractions, first multiply across the numerators and then multiply across the denominators.
× 
= ?
15 × 1 = 15
20 × 4 = 80
can be reduced by dividing both the numerator and denominator by the Greatest Common Factor which is 5.
15 ÷ 5 = 3
80 ÷ 5 = 16
Therefore, × = 
The quadrilaterals whose consecutive and opposite angles are always congruent are the square and the rectangle. All of the angles of the square and the rectangle are 90 degrees. The consecutive angles of the parallelogram and the rhombus are not equal.
The period of the function is 2pi
