Answer:
h=12 A=144 sq. cm.
Step-by-step explanation:
pythagoream therom:
9^2+h^2=15^2
81+h^2=225
h^2=225-81
h^2=144
Sq. rt h^2=sq. rt 144
h=12cm
1/2(b1+b2)h
1/2(5+19)12
1/2(24)12
1/2(288)
a=144
A number can replaced with a variable like x
(X+3)4=16
4x+12=16
4x=4
X=1
(X/4)+3=24
X/4=21
X=84
Acute........................
30 + 70 + D = 180
100 + D = 180
D = 80°
