Doctors use the term maximum heart rate (mhr) when referring to the quantity found by
starting with 220 beats per minute and subtracting 1 beat per minute for each year of a
person’s age. doctors recommend exercising 3 or 4 times each week for at least 20 minutes
with your heart rate increased from its resting heart rate (rhr) to its training heart rate
(thr), where thr = rhr + .65(mhr – rhr)
which of the following is closest to the thr of a 43-year-old person whose rhr is 54 beats
per minute?
a. 197
b. 169
c. 162
d. 134
e. 80

Given: ad¯¯¯¯¯ is an altitude. prove: ab2+ac2=cb2 right triangle a b c with right angle a. point d lies on side b c and segment a d is drawn. angle a d c is a right angle. drag and drop a reason into each box to correctly complete the two-column proof. statement reason ad¯¯¯¯¯ is an altitude, and ∠bac is a right angle. given ∠adb and ∠adc are right angles. definition of altitude ∠bac≅∠bda ? ∠bac≅∠adc ? ∠b≅∠b ? ∠c≅∠c reflexive property of congruence △abc∼△dba ? △abc∼△dac aa similarity postulate abbd=cbab ? ab2=(cb)(bd) cross multiply and simplify. acdc=cbac polygon similarity postulate ac2=(cb)(dc) cross multiply and simplify. ab2+ac2=ab2+(cb)(dc) addition property of equality ab2+ac2=(cb)(bd)+(cb)(dc) substitution property of equality ab2+ac2=(cb)(bd+dc) ? bd+dc=cb segment addition postulate ab2+ac2=cb2 substitution property of equality