The side of the rhombus is 29 and the diagonal is 42. Find the area of the rhombus

Let’s construct the ВD diagonal. The diagonals of the rhombus intersect at right angles and at the point of intersection are divided in half, then AO = AC / 2 = 42/2 = 21 cm.

Triangle AOB is rectangular, in which, according to the Pythagorean theorem, we determine the length of the leg OB.

ОВ ^ 2 = AB ^ 2 – AO ^ 2 = 841 – 441 = 400.

OB = 20 cm.

Saov = AO * ВO / 2 = 21 * 20/2 = 210 cm2.

The diagonals of the rhombus divide it into four equal triangles, then Savsd = 4 * Saov = 4 * 210 = 840 cm2.

Answer: The area of the rhombus is 840 cm2.



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