Answer:
SEE BELOW
Explanation:
1. find value of m
a^2 + b^2 = c^2
7.5^2+10^2=c^2
15+100=c^2
115=c^2
square it
=10.7 (not answer)
a^2+b^2=c^2
10.7^2+30^2=c^2
114.49+900=c^2
1014.49=c^2
square it
m=31.9
2.20^2 + 21^2 = 841
29^2=841
yes the triangle is right angled !!!
hope this helps :)