The diagonals of the rhombus are 3: 4 and the side is 50cm. Find the diagonals of the rhombus.
The diagonals of the rhombus intersect at right angles and the intersection point is halved:
AO = OC = AC / 2;
BO = OD = BD / 2.
Consider the ABO triangle. Behind the Pythagorean theorem, you can find the segments BO and AO:
AB ^ 2 = AO ^ 2 + BO ^ 2.
Since the diagonals of the rhombus are related as 3: 4, the segments AO and BO will be equal to half of this length and are related as: (3/2) 🙁 4/2) = 1.5: 2. Thus, we express the segments AO and BO as follows:
1.5x is the length of the AO segment;
2x – length of the BO segment;
(1.5x) ^ 2 + (2x) ^ 2 = 50 ^ 2;
2.25x ^ 2 + 4x ^ 2 = 2500;
6.25x ^ 2 = 2500;
x ^ 2 = 2500 / 6.25 = 400;
x = √400 = 20;
AO = 1.5 20 = 30 cm;
BO = 2 * 20 = 40 cm.
AC = AO · 2;
AC = 30 2 = 60 cm;
BD = BO · 2;
ВD = 40 2 = 80 cm.
Answer: the diagonals of the rhombus are 60 cm and 80 cm.