The change in kinetic energy (in joules) as a horse accelerates from canter to gallop is found using the expression 1/2×350×(12^2-6^2). which is the change in kinetic energy?
(i put ^ for square, like 12 squared by 2.)

1. ∠1 is complementary to ∠2 and ∠3 is complementary to ∠2. subtraction property of equality 2. m∠1 + m∠2 = 90 and m∠3 + m∠2 = 90 substitution 3. m∠1 + m∠2 = m∠3 + m∠2 definition of complementary 4. m∠1 = m∠3 given