well to solve this you will need the formula of a triangle: 1/2 (bh)
b= 3cm
h=4.5cm
so you would multiply those: 13.5cm but we’re not done because the formula says that it’s only half of bh
13.5 divided by 2 is 6.75cm
and with area it’s always square so the answer would be 6.75cm2 (i don’t know how to get the 2 small)