The area of a triangle can be found by multiplying the base times the one-half the height.
If a triangle for instance, has a base of length 6 inches and a height of 4 inches, its area is 6*2=12 square inches
Of course, in your case you could be helped by
The Side Angle Side Formula = ½ (number of the base ×number of the side) × sin(...°)
For example, if the base equals 42 and one side equals 16 and when you measure the angle between them you find that it equals 68 then the formula is : ½ (42 ×16) × sin(68 °)
The Side Angle Side formula simply is an application of the sine function to find the height.
PS: when we are talking about "base" we mean the longest side of the triangle