Question

find the area of parallelogram ABCD given AB=12cm, AD=20cm and angle A = 30 degrees

Answer 1

@hartnn

Answer 2

area=absinA=12*20*sin30=120 cm^2

Answer 3

can u do that without the sin - i am just in trig - is it the height 6sqrt3

Answer 4

not in trig sorry just in geometry

Answer 5

ok, in geometry u use the formula area=bh. but to calculate the height from the given length of sides and the given angle u must use trigonometry.

Answer 6

well since a 30 60 90 hypotenuse is s which is 12
and height is sqrt3/2 and bottom is s/2

Answer 7

so figured out height is 6sqrt 3?

Answer 8

if u take the 12 cm side as a base, the height is 20sin30=10. then the area becomes 12*10=120.
if u take the 20 cm side as a base, the height is 12sin30=6. then the area becomes 20*6=120.
thus the length of the height depends on which side u take as a base.

Answer 9

i need it without trig i am in geometry - i know that it is a 30 60 90 triangle

Answer 10

yes, but the possible heights are 10 and 6, but not 6sqrt3.

Answer 11

In a 30-60-90 triangle, the corresponding sides are: 1:sqrt(3):2
so the side opposite 30 degrees is 1/2 the length of the hypotenuse.

So the height of the parallelogram is either 20/2 or 12/2.
Area = base * height = 12 * 20/2 = 120 or 20 * 12/2 = 120.