tolong jawab secepatnya ya yg no 2

a.
KN^2 = 15^2 - 12^2
KN^2 = 225 - 144
KN = √ 81
KN = 9 cm

Keliling
= 5 + 15 + 17 + 9
= 46 cm

b.
Luas
= 1/2 ( a + b ) x t
= 1/2 ( 5 + 17 ) x 9
= 1/2 ( 22 ) x 9
= 99 cm^2