Answer:
21cm^2
Explanation:
1/2 5 x 6 = 15
1/2 x 4 x 3 = 6
15+6 = 21cm^2
If you was working out a missing angle you would 1/2 the longest lines and add them up then add the shortest line
ie) 1/2 6 = 3
1/2 3 5 = 2.5
36+ 25 = 61 sq rt
= 7.81
Then find your multiplier 6/5 = 1.2 you take this multiply by 10
12 and half it = 6 x 7.810 = 46.86 = your angle for the larger triangle.
The smaller triangle missing angle is same method but you keep the multiplier without multiplying by 10 or halfling it, you need to half the 2 sides first then add them to the smaller side found doing Pythagoras and find you r multiplier large side/ second largest side = x then times x by the multiplier two sides halved and smaller side added. = 3 sq 4 sw = 9+16 = 25 sq = 5 large then + half 4 = 2 + 3
= 2.5+ 2 + 3 = 7.5
then 5/4 = 1.25
=1.25 x 10 = 12.5 then half it = 6.5 then multiply it by 7.5
=6.5 x 7.5 = 48.75 missing angle smaller triangle.