13 A triangle has the same area as a 6-by-8 rectangle. The base of
the triangle is 8. Find the altitude of the triangle.
3 Find the total area of each figure. (In each figure the triangle is
mounted on a rectangle.)
14 Lines CF and AB are parallel and 10 mm apart. Several triangles
with base AB and a vertex on CF have been drawn below.
Which triangle has the largest area? Explain.
D
E
F
4 Find the altitude of a triangle if its base is 7 and its area is 21.
A
5 Find the area of an isosceles triangle with sides 10,10, and 16.
16
15 Find the area of the shaded region.
6 Find the area of a parallelogram of base 17 and height 11.
10 7
10
7 Find the base of a parallelogram of height 3 and area 42.
8 Find the area of
B
16 In a triangle, a base and its altitude are in a ratio of 3:2. The
triangle's area is 48. Find the base and the altitude.
a
each obtuse triangle.
17 Find the area of the
shaded triangular region.
t—7
9 Find the area of
a
each triangle.
18 Given: QT = 12, PR = 15,
12V2
10 Find the area of each
parallelogram to the
nearest tenth.
PS = 10
Find: a The area of APQR
b RQ
20
a
10/!
r!
I
2 Find the area of AAOC.
B01.8)
15
4S'
1
19 a Find the area of a triangle whose sides are 25, 25, and 14.
b Find the area of a right triangle whose legs are 9 and 40.
c Find the area of an isosceles triangle with hypotenuse 18.
20 Find the area of an equilateral triangle with a perimeter of 45 m.
A
(11,0)
x-axis
21 Find the area of each parallelogram to the nearest tenth.
b
/T3^
'10
120°
14
17