Answer:
area of the BCD triangle=1/2×10×9
=45
area of the ABD triangle=1/2×10×3
=15
Total area=45+15
=60 square centimetres
Step-by-step explanation:
(10 - 8)/(-21 + 9)= 12/-12= -1
y - 8 = -1(x + 9)
y - 8 = -x - 9
y = -x - 1
