last math question…?
In a parallelogram ABCD, the diagonal AC is at right angles to AB. If AB=12 cm and BC=13 cm, find the area of the parallelogram.
thnx =)))
Favorite Answer
by phytagorean theorem:
BC^2 = AB^2 + AC^2
AC^2 = BC^2 – AB^2
AC = sqrt(BC^2 – AB^2)
CAB is a right triangle with BC the hypotenuse.
(AC)² = (BC)² – (AB)² = 13² – 12² = 169 – 144 = 25
AC = 5
Calculate the area of triangle CAB.
Area = ½bh = ½*AC*AB = ½*5*12 = 30
Triangle ACD is congruent to triangle CAB so the area of the parallelogram ABCD is:
2*30 = 60 cm²
ab^2 = 144
bc^2 =169
169 – 144 =25
sqrt of 25 = 5
AC = 5
AB = 12
5*12 = 60
Area = 60cm
ab^2 = 144
bc^2 =169
169 – 144 =25
sqrt of 25 = 5
AC = 5
AB = 12
5*12 = 60
Area = 60cm
ab^2 = 144
bc^2 =169
169 – 144 =25
sqrt of 25 = 5
AC = 5
AB = 12
5*12 = 60
Area = 60cm