a=41.5m, c=34.5m, B=151.5degrees
2007-12-05 02:35:12 · 9 answers · asked by Princess 2 in Science & Mathematics ➔ Mathematics
using law of cosines find side b
so as per law of cosines
b^2=a^2+c^2-2cacosB
so substuting values we get
b^2=(41.5)^2+(34.5)^2-2*41.5*34.5*cos(151.5degrees)
b^2=1722.25+1190.25-2863.5*cos(151.5degrees)
b^2=2912.5-2863.5*(-.8788)
b^2=2912.5+2516.44
b^2=5428.94
b=73.68
now use the heros formula to find the area
sqrt[s(s-a)(s-b)(s-c)]
where s=a+b+c/2
in the given problem s=[41.5+34.5+73.68]/2
s=74.84
so now substuting all the values in the formula
sqrt[74.84(74.84-41.5)(74.84-34.5)(74.84-73.68)]
sqrt[74.84(33.34)(40.34)(1.16)]
sqrt[116759.777]
341.70
so the area of the triangle is 341.70m^2
2007-12-05 02:49:21 · answer #1 · answered by Siva 5 · 0⤊ 1⤋
Draw your cardinal points. Start from the x-axis and construct 151.5 degrees going anti-clockwise. Draw a line from x = 0 to meet this angle. The base at x = 0 is the angle B. BA is along the x-axis. BC is the line from x = 0 that meets the obtuse angle line. So the base of the triangle is: 34.5 m. The height, h is found by construction to be 41.5sin 28.5. The 28.5degrees is the difference between 180 and 151.5 degree. So the area of the triangle is:
Area = 1/2(b)(h) = 1/2(34.5)(41.5 sin 28.5) = 341.6 sq. m.
2007-12-05 03:09:49 · answer #2 · answered by man_mus_wack1 4 · 0⤊ 0⤋
It's 12. You have to factor in that the wind might be blowing, so you take the first derivative of the square root of Green's Theorem.
Champagne Wishes and Caviar Dreamz
2007-12-05 02:44:09 · answer #3 · answered by true_wahoo 3 · 0⤊ 3⤋
A=1/2BH
so since you have not given any visual cues to your question i can't really do your problem...if you need the length for "b", use the Trigonometric Laws of Sines, Cosines, and Tangent
2007-12-05 02:47:16 · answer #4 · answered by Pastor_of_Muppets 4 · 0⤊ 2⤋
Area = |c*sin(B)|*a/2
Why? well for an explanation you'll have to look into your textbooks because it requires a lot of diagrams which i cannot draw with text.
2007-12-05 02:53:17 · answer #5 · answered by Morkeleb 3 · 0⤊ 0⤋
Rach A, ur wrong because one of those numbers is a degree, not a side, but yea , talk to ur teacher
2007-12-05 02:43:23 · answer #6 · answered by anomonous person 2 · 1⤊ 2⤋
Robert L is right. (I am doing a degree in maths)
2007-12-06 04:48:17 · answer #7 · answered by golden_everglade 2 · 0⤊ 0⤋
Well, add all those together, and then, divide the sum by three.
you should get 75.7
but if you need help with homework, you should be asking your teacher or someone else, you shouldnt be getting answers online.
2007-12-05 02:39:50 · answer #8 · answered by well_hello 2 · 0⤊ 3⤋
Area = (a*c*sin B)/2
Area = (41.5)(34.5)(0.4848)/2
Area = 347.1 m²
2007-12-05 02:51:20 · answer #9 · answered by Robert L 7 · 1⤊ 1⤋