The perimeter of a parallelogram is 112 cm, and its two sides are 5: 3. Find the sides of the parallelogram.
Given:
ABCE – parallelogram,
AB: BC = 5: 3,
the perimeter of ABCE is 112 centimeters.
Find the lengths of the sides of the parallelogram ABCE: AB, CE, BC, AE -?
Decision:
Consider a parallelogram ABCE. Its opposite sides are equal to each other, then BC = AE, AB = CE.
Let the length of the BC side be 3x centimeters, then the length of the AB side = 5 * x centimeters. We know that the ABCE perimeter is 112 centimeters. Let’s make the equation:
P avce = AB + CE + BC + AE;
112 = 5 * x + 5 * x + 3 * x + 3 * x;
112 = x * (5 + 5 + 3 + 3)
16 * x = 112;
x = 112: 16;
x = 7 centimeters;
3 * 7 = 21 centimeters – the lengths of the sides BC and AE;
5 * 7 = 35 centimeters – the lengths of the sides AB and CE.
Answer: 21 centimeters; 21 centimeters; 35 centimeters; 35 centimeters.