Answer:
A = 23.6 units^2
Step-by-step explanation:
Let the base be 8 (as shown).
Find the height of the triangle: Find the supplement of the 100 degree angle; it is (180 - 100), or 80 degrees. The side "opposite" this 80-degree angle is the height of the triangle:
height
sin 80 degrees = ---------------
6
and so the height of the triangle is h = 6 sin 80 degrees, or 5.91 units.
The area of the triangle is found using A = (1/2)(base)(height), which here amounts to:
A = (1/2)(8 units)(5.91 units), or
A = 23.64 units^2, or A = 23.6 units^2
