Peter R. answered 03/16/23
Experienced Instructor in Prealgebra, Algebra I and II, SAT/ACT Math.
Part (A) The drawing shows a right triangle KML where you know two of the three sides, so can use Pythagorean Theorem: a2 + b2 = h2. In this case KM2 + 352 = 372 → KM2 + 1225 = 1369 → KM2 = 1369 - 1225 = 144
So KM = √144 = 12 cm. (Why do they need it rounded to nearest hundredth?)
Part (B) Now we have right triangle KMJ with sides 12 and 12 opposite the hypotenuse.
122 + 122 = JK2 → 144 + 144 = 288 = JK2
So JK = √288 = 16.97056..., rounds to 16.97 cm.
Now the perimeter of ΔJKL is 12 + 35 + 37 + 16.97 = 100.97 cm.