How do you find the area of #triangle ABC# given #A=138^circ, b=10, c=20#? Trigonometry Triangles and Vectors Area of a Triangle 1 Answer Ratnaker Mehta Jan 24, 2017 #66.91sq.units(4dp).# Explanation: The Area of #Delta ABC=1/2bcsinA=(1/2)(10)(20)sin138^@# #~~(100)(0.6691)=66.91sq.units(4dp).# Answer link Related questions How do you find the area of a triangle with 3 sides given? What is the area of a equilateral triangle with a side of 12? How do you find the area of a triangleABC, if #angleC = 62^@#, #b = 23.9# , and #a = 31.6#? How do you find the area of a triangleGHI, if #angleI = 15^@#, #g = 14.2# , and #h = 7.9#? What is Heron's formula? When do you use Heron's formula to find area? How do you find the area of a triangle ABC, if #a = 23#, #b = 46# , and #c = 41#? Question #f2e4c How do you find the area of the triangle given c= 4, A= 37 degrees, B= 69 degrees? How do you find the area of the triangle given C=85 degrees, a= 2, B= 19 degrees? See all questions in Area of a Triangle Impact of this question 1495 views around the world You can reuse this answer Creative Commons License