In triangle DEF, side lengths are DE = 75 cm, EF = 100 cm, and DF = 125 cm. Let M be the midpoint of side DF. Find the length of EM.
Show answer & explanation
Correct answer: B
Explanation
Given:
DE = 75 cm
EF = 100 cm
DF = 125 cm
M, the midpoint of DF
By the formula:
75² = 5625
100² = 10000
125² = 15625
m = 1/2 √[2(5625 + 10000) − 15625]
= 1/2 √[2(15625) − 15625]
= 1/2 √15625
= 125/2
= 62.5 cm