the height of a triangle is 7cm greater than its base and its area is 15cm squared. find the value of its height

Step-by-step explanation:

Let base be b, height be h

h = 7+b or we can say that b = h -7

A = 15 cm²

General formula for area of a triangle

A = b · h

Substitute what we know to find the height h

15 = (h-7) · h

15 = h² -7h

0 = h²-7h -15

h = (7 ±√49 + 4·1·15)/2

h = (7 ±√109)/2

h ≈ -1.72 reject this solution because height cannot be negative

h ≈ 8.72 cm

0.02

step-by-step explanation:

time of 9 192 631 770 periods of the radiation corresponding to the transition between the 2 hyperfine levels of the ground state of the caesium 133 atom at 0 k (but other seconds are sometimes used in astronomy)