# Spectrum Math Grade 7 Chapter 5 Lesson 10 Answer Key Area: Triangles

This handy Spectrum Math Grade 7 Answer Key Chapter 5 Lesson 5.10 Area: Triangles provides detailed answers for the workbook questions

## Spectrum Math Grade 7 Chapter 5 Lesson 5.10 Area: Triangles Answers Key

To find the area of a triangle, find $$\frac{1}{2}$$ the product of the measure of its base and its height.
A = $$\frac{1}{2}$$ × b × h

b = 6 in. and h = 8 in. Find A.
A = $$\frac{1}{2}$$ × b × h
A = $$\frac{1}{2}$$ × 6 × 8
A = 24 in.2

The height is the distance from the base to the highest point on the triangle using a line perpendicular to the base.

Find the area of each triangle.

Question 1.
a.

area = _____________ m2
area = 210 m2

Explanation:
A = $$\frac{1}{2}$$ × b × h
Given,
b = 21 m. and h = 20m
A = $$\frac{1}{2}$$ × b × h
A = $$\frac{1}{2}$$ × 21 × 20
A = $$\frac{1}{2}$$ x 420
A = 210 m.2

b.

area = ______________ ft.2
area = 14 ft.2

Explanation:
A = $$\frac{1}{2}$$ × b × h
Given,
b = 7ft. and h = 4ft
A = $$\frac{1}{2}$$ × b × h
A = $$\frac{1}{2}$$ × 7 × 4
A = $$\frac{1}{2}$$ x 28
A = 14 ft.2

c.

area = ______________ in.2
area = 199.5 in.2

Explanation:
A = $$\frac{1}{2}$$ × b × h
Given,
b = 19 in. and h = 21 in
A = $$\frac{1}{2}$$ × b × h
A = $$\frac{1}{2}$$ × 19 × 21
A = $$\frac{1}{2}$$ x 399
A = 199.5 in.2

Question 2.
a.

area = _______________ cm2
area = 270 cm2

Explanation:
A = $$\frac{1}{2}$$ × b × h
Given,
b = 36 cm. and h = 15 cm
A = $$\frac{1}{2}$$ × b × h
A = $$\frac{1}{2}$$ × 36 × 15
A = $$\frac{1}{2}$$ x 540
A = 270 cm.2

b.

area = _______________ m2
area = 162 m2

Explanation:
A = $$\frac{1}{2}$$ × b × h
Given,
b = 18 m. and h = 18 m
A = $$\frac{1}{2}$$ × b × h
A = $$\frac{1}{2}$$ × 18 × 18
A = $$\frac{1}{2}$$ x 324
A = 162 m.2

c.

area = _______________ cm2
area = 272 cm2

Explanation:
A = $$\frac{1}{2}$$ × b × h
Given,
b = 32 cm. and h = 17 cm
A = $$\frac{1}{2}$$ × b × h
A = $$\frac{1}{2}$$ × 32 × 17
A = $$\frac{1}{2}$$ x 544
A = 272 cm.2

Question 3.
a.

area = ______________ ft.2
area = 348 ft.2

Explanation:
A = $$\frac{1}{2}$$ × b × h
Given,
b = 29 ft. and h = 24 ft.
A = $$\frac{1}{2}$$ × b × h
A = $$\frac{1}{2}$$ × 29 × 24
A = $$\frac{1}{2}$$ x 696
A = 348 ft.2

b.

area = _______________ in.2
area = 230 in.2

Explanation:
A = $$\frac{1}{2}$$ × b × h
Given,
b = 23 in. and h = 20 in
A = $$\frac{1}{2}$$ × b × h
A = $$\frac{1}{2}$$ × 23 × 20
A = $$\frac{1}{2}$$ x 460
A = 230 in.2

c.

area = _______________ cm2
A = $$\frac{1}{2}$$ × b × h
A = $$\frac{1}{2}$$ × b × h
A = $$\frac{1}{2}$$ × 25 × 25
A = $$\frac{1}{2}$$ x 625