Em um triângulo ABC o vértice A tem coordenadas (2, -1) e a reta suporte do lado BC tem equação x + 2y + 20 = 0. Nessas condições a altura relativa ao lado BC é: a) 4√3
b) √5
c) 4√2
d) 2√5
e) 4√5

the answer is c.) yes, [triangle]klp can be reflected across the line containing [line]kp and then translated so that p is mapped to m.

the reason is this:

looking at the triangles visually we can see they share the same features. using rigid transfromations we can reflect it over [line]kp then all we need to do is translate up.

0.61 has 2 decimal places, so we put the decimal digits of 0.61, 61 over 1 followed by the number of zeroes equal to the number of decimal places, 

2:     61/1 = 61/100.