Hiya, hope these help! :)
Formula for a triangle: A=1/2(base of triangle x height of triangle)
Triangle a: 120cm²
A= 1/2(b x h)
A= 1/2(20 x 12)
A= 1/2 (240)
A= 120
Triangle b: 72cm²
A= 1/2(b x h)
A= 1/2(12 x 12)
A= 1/2 (144)
A= 72
Triangle c: 154cm²
A= 1/2 (b x h)
A= 1/2 (28 x 11)
A= 1/2 (308)
A= 154
Triangle d: 49cm²
A= 1/2 (b x h)
A= 1/2 (14 x 7)
A= 1/2 (98)
A= 49
Triangle e: 105cm²
A= 1/2 (b x h)
A= 1/2 (14 x 15)
A= 1/2 (210)
A= 105
Triangle f: 160cm²
A= 1/2 (b x h)
A= 1/2 (20 x 16)
A= 1/2 (320)
A= 160
Triangle g is missing the base number! It's not shown fully in the screenshot, therefore it will just be whatever answer is leftover! :)
Triangle h: 288cm²
A= 1/2 (b x h)
A= 1/2 (36 x 16)
A= 1/2 (576)
A= 288
Let me know if you have any more questions!