SOLUTION: The length of a rhombus is 10 cm an measured angle A is 60 degrees. Find the length of the longer diagonal AC.

Algebra.Com
Question 191791: The length of a rhombus is 10 cm an measured angle A is 60 degrees. Find the length of the longer diagonal AC.
Answer by RAY100(1637)   (Show Source): You can put this solution on YOUR website!
RHOMBUS = ALL SIDES EQUAL
f ----d.................................c
!
!
!
!
!
a....................................b---e
Let abcd be rhombus
angle dcb = 60 deg
therefore angle bcd =60, angle bce = 30 deg
bce is a 30 - 60 - 90 right triangle
bc =10 (given)
be = 5 (given 1/2 of bc due to 30-60-90 proportions)
ce = 5sq rt 3 ( given 30-60-90 proportions
triangle ae-ce-ca is rt triangle with sides (10 +5 =15) - (5 sq rt 3) - diagonal (ac)
using pythagorous c^2 = a^2 = b^2

(ac)^2 = (ae)^2 + (ce)^2
ac^2 = 15^2 + (5sq rt 3)^2
ac^2 = 225 + (25*3)
ac^2 = 300
ac = sq rt 300 = 10 sq rt 3
short diagonal is bd = 5 sq rt 7 in similar fashion
bd^2= 10^2 + ( 5sq rt 3)^2 = 175

RELATED QUESTIONS

A rhombus has an area of 200 cm^2 and one of its interior angles is 110 degrees a. Find... (answered by ikleyn)
The diagonals of a rhombus are in the ratio 1:3. If each side of the rhombus is 10 cm... (answered by ikleyn)
ABCD is a rhombus of side 15cm. The diagonal AC is of length 20cm. Find the angle between (answered by Boreal)
A rhombus has an 8m side and a 60 degree angle, what is the length of each... (answered by KMST)
The perimeter of a rhombus is 60. If the length of its longer diagonal measures 24, what (answered by edjones)
In a rhombus one side 10 cm and an angle in 37°. Find the area and find the length of a... (answered by greenestamps)
The side of a rhombus is half the longer diagonal.The height of the rhombus is 3cm and... (answered by Fombitz,ikleyn)
A rhombus has sides of length 6 cm. One of its diagonals is 10 cm long. Find the length... (answered by midwood_trail)
The sides of a parallelogram are 55 cm and 84cm. The smaller angle of the parallelogram... (answered by ikleyn)